qcacmn: Returns NULL if opmode mismatched when get vdev from psoc

When get vdev by opmode from psoc, objmgr will return vdev without
getting reference if vdev list isn't null and no matched vdev with
opmode.

Change-Id: I1bb29f074155a40c38a21a9f0534d5f756862031
CRs-Fixed: 2758693

umac/cmn_services/obj_mgr/src/wlan_objmgr_psoc_obj.c

@@ -1080,6 +1080,7 @@ struct wlan_objmgr_vdev *wlan_objmgr_get_vdev_by_opmode_from_psoc_debug(
 			break;
 		}
 		wlan_vdev_obj_unlock(vdev);
+		vdev = NULL;
 	}
 	wlan_psoc_obj_unlock(psoc);
 
@@ -1119,6 +1120,7 @@ struct wlan_objmgr_vdev *wlan_objmgr_get_vdev_by_opmode_from_psoc(
 			break;
 		}
 		wlan_vdev_obj_unlock(vdev);
+		vdev = NULL;
 	}
 	wlan_psoc_obj_unlock(psoc);