x86/oprofile: Modify initialization of num_virt_counters

Models that do not yet support counter multiplexing have to setup
num_virt_counters. This patch implements the setup from num_counters
if num_virt_counters is not set. Thus, num_virt_counters must be setup
only for multiplexing support.

Signed-off-by: Robert Richter <robert.richter@amd.com>
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 826f391..82ee2951 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -674,6 +674,9 @@
 	if (ret)
 		return ret;
 
+	if (!model->num_virt_counters)
+		model->num_virt_counters = model->num_counters;
+
 	init_sysfs();
 	using_nmi = 1;
 	printk(KERN_INFO "oprofile: using NMI interrupt.\n");