x86/oprof: adjust off-by-one counter range checks

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/oprofile/xenoprof.c
+++ b/xen/arch/x86/oprofile/xenoprof.c
@@ -24,7 +24,7 @@ int xenoprof_arch_counter(XEN_GUEST_HAND
     if ( copy_from_guest(&counter, arg, 1) )
         return -EFAULT;
 
-    if ( counter.ind > OP_MAX_COUNTER )
+    if ( counter.ind >= OP_MAX_COUNTER )
         return -E2BIG;
 
     counter_config[counter.ind].count     = counter.count;
@@ -61,7 +61,7 @@ int compat_oprof_arch_counter(XEN_GUEST_
     if ( copy_from_guest(&counter, arg, 1) )
         return -EFAULT;
 
-    if ( counter.ind > OP_MAX_COUNTER )
+    if ( counter.ind >= OP_MAX_COUNTER )
         return -E2BIG;
 
     counter_config[counter.ind].count     = counter.count;