Use Q_ENUM instead of obsoleted Q_ENUMS

It fixes the following warning:
Use Q_ENUM instead of Q_ENUMS [clazy-qenums]

In addition, it amends 8588cf268f
where WidgetStyle got removed.

Change-Id: I4d72dd762a2f18ba8886360b3581b4ef19bf4c5e
Reviewed-by: hjk <hjk@qt.io>

src/plugins/valgrind/callgrind/callgrindcontroller.h

@@ -38,8 +38,6 @@ namespace Callgrind {
 class CallgrindController : public QObject
 {
     Q_OBJECT
-    Q_ENUMS(Option)
-
 public:
     enum Option {
         Unknown,
@@ -48,6 +46,7 @@ public:
         Pause,
         UnPause
     };
+    Q_ENUM(Option)
 
     CallgrindController();
     ~CallgrindController() override;