[PATCH] uml - hostfs: avoid buffers

Use this:
	.set_page_dirty = __set_page_dirty_nobuffers,

We already dropped the inclusion of <linux/buffer_head.h>, and we don't have a
backing block device for this FS.

"Without having looked at it, I'm sure that hostfs does not use buffer_heads.
So setting your ->set_page_dirty a_op to point at __set_page_dirty_nobuffers()
is a reasonable thing to do - it'll provide a slight speedup."

This speedup is one less spinlock held and one less conditional branch, which
isn't bad.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>