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>

drivers/vdpa/ifcvf/ifcvf_main.c

@@ -290,16 +290,16 @@ static int ifcvf_request_config_irq(struct ifcvf_adapter *adapter)
 	struct ifcvf_hw *vf = &adapter->vf;
 	int config_vector, ret;
 
-	if (vf->msix_vector_status == MSIX_VECTOR_DEV_SHARED)
-		return 0;
-
 	if (vf->msix_vector_status == MSIX_VECTOR_PER_VQ_AND_CONFIG)
-		/* vector 0 ~ vf->nr_vring for vqs, num vf->nr_vring vector for config interrupt */
 		config_vector = vf->nr_vring;
-
-	if (vf->msix_vector_status ==  MSIX_VECTOR_SHARED_VQ_AND_CONFIG)
+	else if (vf->msix_vector_status ==  MSIX_VECTOR_SHARED_VQ_AND_CONFIG)
 		/* vector 0 for vqs and 1 for config interrupt */
 		config_vector = 1;
+	else if (vf->msix_vector_status == MSIX_VECTOR_DEV_SHARED)
+		/* re-use the vqs vector */
+		return 0;
+	else
+		return -EINVAL;
 
 	snprintf(vf->config_msix_name, 256, "ifcvf[%s]-config\n",
 		 pci_name(pdev));