vDPA/ifcvf: fix uninitialized config_vector warning

vDPA/ifcvf: fix uninitialized config_vector warning

Static checkers are not informed that config_vector is controlled
by vf->msix_vector_status, which can only be
MSIX_VECTOR_SHARED_VQ_AND_CONFIG, MSIX_VECTOR_SHARED_VQ_AND_CONFIG
and MSIX_VECTOR_DEV_SHARED.

This commit uses an "if...elseif...else" code block to tell the
checkers that it is a complete set, and config_vector can be
initialized anyway

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Message-Id: <20220424072806.1083189-1-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>