Revert "vhost: make msg padding explicit"

This reverts commit 93c0d549c4c5a7382ad70de6b86610b7aae57406.

Unfortunately the padding will break 32 bit userspace.
Ouch. Need to add some compat code, revert for now.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/vhost.h

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