Got the solution by adding a flag variable in action_produce function in mrp.py.

Here is the code... but check it once by yourself.

def action_produce(self, cr, uid, production_id, production_qty, production_mode, context=None):
        """ To produce final product based on production mode (consume/consume&produce).
        If Production mode is consume, all stock move lines of raw materials will be done/consumed.
        If Production mode is consume & produce, all stock move lines of raw materials will be done/consumed
        and stock move lines of final product will be also done/produced.
        @param production_id: the ID of mrp.production object
        @param production_qty: specify qty to produce
        @param production_mode: specify production mode (consume/consume&produce).
        @return: True
        """
        count=0
        stock_mov_obj = self.pool.get('stock.move')
        production = self.browse(cr, uid, production_id, context=context)

        final_product_todo = []

        produced_qty = 0
        if production_mode == 'consume_produce':
            produced_qty = production_qty

        for produced_product in production.move_created_ids2:
            if (produced_product.scrapped) or (produced_product.product_id.id <> production.product_id.id):
                continue
            produced_qty += produced_product.product_qty

        if production_mode in ['consume', 'consume_produce']:
            consumed_products = {}
            check = {}
            scrapped = map(lambda x:x.scrapped, production.move_lines2).count(True)

            for consumed_product in production.move_lines2:
                consumed = consumed_product.product_qty
                if consumed_product.scrapped:
                    continue
                if not consumed_products.get(consumed_product.product_id.id, False):
                    consumed_products[consumed_product.product_id.id] = consumed_product.product_qty
                    check[consumed_product.product_id.id] = 0
                for f in production.product_lines:
                    if f.product_id.id == consumed_product.product_id.id:
                        if (len(production.move_lines2) - scrapped) > len(production.product_lines):
                            check[consumed_product.product_id.id] += consumed_product.product_qty
                            consumed = check[consumed_product.product_id.id]
                        rest_consumed = produced_qty * f.product_qty / production.product_qty - consumed
                        consumed_products[consumed_product.product_id.id] = rest_consumed

            for raw_product in production.move_lines:
                count=0
                for f in production.product_lines:
                    if f.product_id.id == raw_product.product_id.id and count==0:
                        count=count+1
                        consumed_qty = consumed_products.get(raw_product.product_id.id, 0)
                        if consumed_qty == 0:
                            consumed_qty = production_qty * f.product_qty / production.product_qty
                        if consumed_qty > 0:
                            stock_mov_obj.action_consume(cr, uid, [raw_product.id], consumed_qty, production.location_src_id.id, context=context)

        if production_mode == 'consume_produce':
            # To produce remaining qty of final product
            vals = {'state':'confirmed'}
            #final_product_todo = [x.id for x in production.move_created_ids]
            #stock_mov_obj.write(cr, uid, final_product_todo, vals)
            #stock_mov_obj.action_confirm(cr, uid, final_product_todo, context)
            produced_products = {}
            for produced_product in production.move_created_ids2:
                if produced_product.scrapped:
                    continue
                if not produced_products.get(produced_product.product_id.id, False):
                    produced_products[produced_product.product_id.id] = 0
                produced_products[produced_product.product_id.id] += produced_product.product_qty

            for produce_product in production.move_created_ids:
                produced_qty = produced_products.get(produce_product.product_id.id, 0)
                rest_qty = production.product_qty - produced_qty
                if rest_qty <= production_qty:
                   production_qty = rest_qty
                if rest_qty > 0 :
                    stock_mov_obj.action_consume(cr, uid, [produce_product.id], production_qty, context=context)

        for raw_product in production.move_lines2:
            new_parent_ids = []
            parent_move_ids = [x.id for x in raw_product.move_history_ids]
            for final_product in production.move_created_ids2:
                if final_product.id not in parent_move_ids:
                    new_parent_ids.append(final_product.id)
            for new_parent_id in new_parent_ids:
                stock_mov_obj.write(cr, uid, [raw_product.id], {'move_history_ids': [(4, new_parent_id)]})

        wf_service = netsvc.LocalService("workflow")
        wf_service.trg_validate(uid, 'mrp.production', production_id, 'button_produce_done', cr)
        return True


Hope this will resolve your problem.