Replace it.next() with next(it) for py3 compat

[zhongjun]

The Python 2 next() method of iterators was renamed to __next__() on
Python 3. Use the builtin next() function instead which works on Python
2 and Python 3.
This patch was generated by the next operation of the sixer tool:
https://pypi.python.org/pypi/sixer

change:
manila/tests/share/drivers/emc/plugins/vnx/test_emc_vnx.py:
'expect = self._get_req_from_call(iter_expect.next())' to 'expect = self._get_req_from_call(next(iter_expect))'
'actual = self._get_req_from_call(iter_actual.next())' to 'actual = self._get_req_from_call(next(iter_actual))'

[janonymous (janonymous)]

If confirmed , i would like to work on this issue .

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/191557

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/191557
Committed: https://git.openstack.org/cgit/openstack/manila/commit/?id=7c4abe2fcc073ab7e721302811b3a8f241e45876
Submitter: Jenkins
Branch: master

commit 7c4abe2fcc073ab7e721302811b3a8f241e45876
Author: janonymous <email address hidden>
Date: Sun Jun 14 14:34:01 2015 +0530

    Replace it.next() with next(it) for py3 compat

    The Python 2 next() method of iterators was renamed to __next__() on
    Python 3. Use the builtin next() function instead which works on Python
    2 and Python 3.
    This patch was generated by the next operation of the sixer tool:
    https://pypi.python.org/pypi/sixer

    Change-Id: I13948f73f34c396c5cb4d55b636f12b96e62f9f9
    Closes-Bug: #1464935