perf: Fix off by one test in perf_reg_value()

The test should be >= ARRAY_SIZE() instead of > ARRAY_SIZE().
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/20120905123126.GC6128@elgon.mountainSigned-off-by: NIngo Molnar <mingo@kernel.org>

arch/x86/kernel/perf_regs.c

@@ -57,7 +57,7 @@ static unsigned int pt_regs_offset[PERF_REG_X86_MAX] = {
 
 u64 perf_reg_value(struct pt_regs *regs, int idx)
 {
-	if (WARN_ON_ONCE(idx > ARRAY_SIZE(pt_regs_offset)))
+	if (WARN_ON_ONCE(idx >= ARRAY_SIZE(pt_regs_offset)))
 		return 0;
 
 	return regs_get_register(regs, pt_regs_offset[idx]);