rpc_pipefs: clear write bit from top level rpc_pipefs directory

We can't create new files or directories here from userspace, so let's
not pretend that this directory is writable.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/rpc_pipe.c

@@ -1118,7 +1118,7 @@ rpc_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_op = &s_ops;
 	sb->s_time_gran = 1;
 
-	inode = rpc_get_inode(sb, S_IFDIR | 0755);
+	inode = rpc_get_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
 	sb->s_root = root = d_make_root(inode);
 	if (!root)
 		return -ENOMEM;