vhost: make msg padding explicit

There's a 32 bit hole just after type. It's best to
give it a name, this way compiler is forced to initialize
it with rest of the structure.

Reported-by: Kevin Easton <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: mstsirkin

include/uapi/linux/vhost.h

@@ -68,6 +68,7 @@ struct vhost_iotlb_msg {
 
 struct vhost_msg {
 	int type;
+	int padding0;
 	union {
 		struct vhost_iotlb_msg iotlb;
 		__u8 padding[64];