perf/x86/amd: Set the size of event map array to PERF_COUNT_HW_MAX

The entry for PERF_COUNT_HW_REF_CPU_CYCLES is not used on AMD, but is
referenced by filter_events() which expects undefined events to have a
value of 0.

Found via KASAN:

  UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:30
  index 9 is out of range for type 'u64 [9]'
  UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:9
  load of address ffffffff81c021c8 with insufficient space for an object of type 'const u64'
Signed-off-by: NAdam Borowski <kilobyte@angband.pl>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1461749731-30979-1-git-send-email-kilobyte@angband.plSigned-off-by: NIngo Molnar <mingo@kernel.org>

arch/x86/events/amd/core.c

@@ -115,7 +115,7 @@ static __initconst const u64 amd_hw_cache_event_ids
 /*
  * AMD Performance Monitor K7 and later.
  */
-static const u64 amd_perfmon_event_map[] =
+static const u64 amd_perfmon_event_map[PERF_COUNT_HW_MAX] =
 {
   [PERF_COUNT_HW_CPU_CYCLES]			= 0x0076,
   [PERF_COUNT_HW_INSTRUCTIONS]			= 0x00c0,