[PATCH] x86_64: Don't claim too many vectors for TLB flushing

It looks like the new scalable TLB flush code for x86_64 is claiming
one more IRQ vector than it actually uses.

Signed-off-by: Jason Uhlenkott <jasonuhl@sgi.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>