From: Ingo Molnar <mingo@elte.hu>

Now the x86_64 bitop memory clobber problem has been fixed we can remove
this.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>