x86/mce/AMD: Fix logic to obtain block address

x86/mce/AMD: Fix logic to obtain block address

In upcoming processors, the BLKPTR field is no longer used to indicate
the MSR number of the additional register. Insted, it simply indicates
the prescence of additional MSRs.

Fix the logic here to gather MSR address from MSR_AMD64_SMCA_MCx_MISC()
for newer processors and fall back to existing logic for older
processors.

[ Drop nextaddr_out label; style cleanups. ]
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1457021458-2522-4-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>