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/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 343ea63..d35240f 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -676,7 +676,7 @@
 	return err;
 }
 
-int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode)
+int hostfs_mkdir(struct inode *ino, struct dentry *dentry, umode_t mode)
 {
 	char *file;
 	int err;