x86, x2apic: Remove duplicate code for IPI mask routines

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: steiner@sgi.com
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/20110519234637.337024125@sbsiddha-MOBL3.sc.intel.com


Signed-off-by: Ingo Molnar <mingo@elte.hu>