[PATCH] optimize prefetch() usage in list_for_each_xxx

[PATCH] optimize prefetch() usage in list_for_each_xxx

This patch changes list_for_each_xxx iterators

from:
	for (pos = (head)->next, prefetch(pos->next);
	     pos != (head);
             pos = pos->next, prefetch(pos->next))
to:
	for (pos = (head)->next;
	     prefetch(pos->next), pos != (head);
             pos = pos->next)

Reduces my vmlinux .text size by 4401 bytes.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>