oprofile/x86: fix crash when profiling more than 28 events

With multiplexing enabled oprofile crashs when profiling more than 28
events. This patch fixes this.
Signed-off-by: NSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

arch/x86/oprofile/nmi_int.c

@@ -222,7 +222,7 @@ static void nmi_cpu_switch(void *dummy)
 
 	/* move to next set */
 	si += model->num_counters;
-	if ((si > model->num_virt_counters) || (counter_config[si].count == 0))
+	if ((si >= model->num_virt_counters) || (counter_config[si].count == 0))
 		per_cpu(switch_index, cpu) = 0;
 	else
 		per_cpu(switch_index, cpu) = si;