Need to use long long, not long when RMWing a MSR. I think
it's harmless right now, but still should be better fixed
if AMD adds any bits in the upper 32bit of HWCR.

Bug was introduced with the TLB flush filter fix for i386
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>