[PATCH] x86_64: Fix OEM hpet check

Use bitmap_zero instead of bitmap_empty to initialise cpu mask This makes it
actually run reliable instead of relying on stack state.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>