Checking APIC version instead of CPU family to determine XAPIC. Family 6
CPU could have xapic as well.

Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>