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/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index 216b419..d1f53ca 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -346,7 +346,7 @@
 }
 
 /***** Make a directory */
-static int msdos_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+static int msdos_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
 	struct super_block *sb = dir->i_sb;
 	struct fat_slot_info sinfo;