fs: remove the unused mempages parameter

Since the mempages parameter is actually not used, they should be removed.

Now there is only files_init use the mempages parameter,

 	files_init(mempages);

but I don't think the adaptation to mempages in files_init is really
useful; and if files_init also changed to the prototype void (*func)(void),
the wrapper vfs_caches_init would also not need the mempages parameter.

Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/namespace.c

@@ -1791,7 +1791,7 @@ static void __init init_mount_tree(void)
 	set_fs_root(current->fs, ns->root, ns->root->mnt_root);
 }
 
-void __init mnt_init(unsigned long mempages)
+void __init mnt_init(void)
 {
 	struct list_head *d;
 	unsigned int nr_hash;