x86, cpu: Fix show_msr MSR accessing function

There's no real reason why, when showing the MSRs on a CPU at boottime,
we should be using the AMD-specific variant. Simply use the generic safe
one which handles #GPs just fine.

Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/1338562358-28182-3-git-send-email-bp@amd64.org


Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>