x86/debug: Fix/improve the show_msr=<cpus> debug print out

x86/debug: Fix/improve the show_msr=<cpus> debug print out

Found out that show_msr=<cpus> is broken, when I asked a
user to use it to capture debug info about broken MTRR's
whose MTRR settings are probably different between CPUs.

Only the first CPUs MSRs are printed, but that is not
enough to track down the suspected bug.

For years we called print_cpu_msr from print_cpu_info(),
but this commit:

| commit 2eaad1fddd7450a48ad464229775f97fbfe8af36
| Author: Mike Travis <travis@sgi.com>
| Date:   Thu Dec 10 17:19:36 2009 -0800
|
|    x86: Limit the number of processor bootup messages

removed the print_cpu_info() call from all APs.

Put it back - it will only print MSRs when the user
specifically requests them via show_msr=<cpus>.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Mike Travis <travis@sgi.com>
Link: http://lkml.kernel.org/r/1329069237-11483-1-git-send-email-yinghai@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>