qcacmn: Change return value to true if cm ctx is NULL

In case if cm ctx is NULL, the disconnect state check API is returning
false which makes the caller assume vdev is not disconnected.
Hence, change the return value to true in this case.

Change-Id: Iadd52d94d6f561974101aa245ddbfdb1eb301b06
CRs-Fixed: 3246161

umac/mlme/connection_mgr/core/src/wlan_cm_util.c

@@ -1088,7 +1088,7 @@ bool cm_is_vdev_disconnected(struct wlan_objmgr_vdev *vdev)
 
 	cm_ctx = cm_get_cm_ctx(vdev);
 	if (!cm_ctx)
-		return false;
+		return true;
 
 	state = cm_get_state(cm_ctx);