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/sysv/namei.c b/fs/sysv/namei.c
index e474fbc..3368425 100644
--- a/fs/sysv/namei.c
+++ b/fs/sysv/namei.c
@@ -131,7 +131,7 @@
 	return add_nondir(dentry, inode);
 }
 
-static int sysv_mkdir(struct inode * dir, struct dentry *dentry, int mode)
+static int sysv_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
 {
 	struct inode * inode;
 	int err = -EMLINK;