switch vfs_mkdir() and ->mkdir() to umode_t

vfs_mkdir() gets int, but immediately drops everything that might not
fit into umode_t and that's the only caller of ->mkdir()...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 0b5745e..87e46b1 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -395,7 +395,7 @@
  */
 
 static int v9fs_vfs_mkdir_dotl(struct inode *dir,
-			       struct dentry *dentry, int omode)
+			       struct dentry *dentry, umode_t omode)
 {
 	int err;
 	struct v9fs_session_info *v9ses;