Replace Q_DECL_OVERRIDE with override

Change-Id: Iba9c9b77bea8c4ec6915a0cac6aa9c84aaa77dca
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

src/plugins/imageformats/tiff/qtiffhandler_p.h

@@ -63,10 +63,10 @@ public:
     void setOption(ImageOption option, const QVariant &value) override;
     bool supportsOption(ImageOption option) const override;
 
-    bool jumpToNextImage() Q_DECL_OVERRIDE;
-    bool jumpToImage(int imageNumber) Q_DECL_OVERRIDE;
-    int imageCount() const Q_DECL_OVERRIDE;
-    int currentImageNumber() const Q_DECL_OVERRIDE;
+    bool jumpToNextImage() override;
+    bool jumpToImage(int imageNumber) override;
+    int imageCount() const override;
+    int currentImageNumber() const override;
 
     enum Compression {
         NoCompression = 0,