[PATCH] uml: adapt asm/futex.h to our arch

Follow up to 4732efbeb997189d9f9b04708dc26bf8613ed721 - uml must just reuse
as-is the backing architecture support. There is a micro-fixup is needed for the
included file, which won't affect i386 behaviour at all.

I've not tested compilation on x86_64, only on x86, but the code is almost the
same except the culprit test, so everything should be ok on x86_64 too.

Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>