NFS: mount option parser chokes on proto=

The new text-based NFS mount option parsing logic doesn't recognize any
valid transport protocols due to a silly mistake in the protocol token
matching logic.  This prevents basic mount requests such as:

   mount.nfs server:/export /mnt -o proto=tcp

from working with the new text-based NFS mount API.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/super.c

@@ -911,13 +911,13 @@ static int nfs_parse_mount_options(char *raw,
 			kfree(string);
 
 			switch (token) {
-			case Opt_udp:
+			case Opt_xprt_udp:
 				mnt->flags &= ~NFS_MOUNT_TCP;
 				mnt->nfs_server.protocol = IPPROTO_UDP;
 				mnt->timeo = 7;
 				mnt->retrans = 5;
 				break;
-			case Opt_tcp:
+			case Opt_xprt_tcp:
 				mnt->flags |= NFS_MOUNT_TCP;
 				mnt->nfs_server.protocol = IPPROTO_TCP;
 				mnt->timeo = 600;
@@ -936,10 +936,10 @@ static int nfs_parse_mount_options(char *raw,
 			kfree(string);
 
 			switch (token) {
-			case Opt_udp:
+			case Opt_xprt_udp:
 				mnt->mount_server.protocol = IPPROTO_UDP;
 				break;
-			case Opt_tcp:
+			case Opt_xprt_tcp:
 				mnt->mount_server.protocol = IPPROTO_TCP;
 				break;
 			default: