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/ramfs/inode.c b/fs/ramfs/inode.c
index 462ceb3..61972be 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -106,7 +106,7 @@
 	return error;
 }
 
-static int ramfs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
+static int ramfs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
 {
 	int retval = ramfs_mknod(dir, dentry, mode | S_IFDIR, 0);
 	if (!retval)