cinder scheduler has a comment error

[周云飞]

The function backend_passes in cinder/scheduler/filters/capabilities_filter.py has an error in the return comment(https://github.com/openstack/cinder/blob/master/cinder/scheduler/filters/capabilities_filter.py#L94). The comment is "Return a list of backends that can create resource_type.", but actually it returns a bool value.

The function backend_passes is similar with function _satisfies_extra_specs wchih in same class.The previous code was very small, so I pasted it.
def backend_passes(self, backend_state, filter_properties):
        """Return a list of backends that can create resource_type."""
        # Note(zhiteng) Currently only Cinder and Nova are using
        # this filter, so the resource type is either instance or
        # volume.
        if not self._satisfies_extra_specs(backend_state.capabilities,
                                           filter_properties):
            LOG.debug("%(backend_state)s fails resource_type extra_specs "
                      "requirements", {'backend_state': backend_state})
            return False
        return True

So the comments in this line should change from"Return a list of backends that can create resource_type." to "Return a bool value which check if capabilities satisfactory resource type requirements."

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/cinder/+/846901