Fix some compiler warnings.

As it turns out, we had an overloaded virtual from an earlier era,
with the extra parameter never used.  So cleaning that up was a
bonus to remove the compiler warning.

Change-Id: I780287f8a5d2b0a1ec84ec62c88ba50e051f372b
Reviewed-by: Jonas Rabbe <jonas.rabbe@nokia.com>

src/plugins/qt7/qt7movierenderer.mm

@@ -401,6 +401,8 @@ void QT7MovieRenderer::setMovie(void *movie)
 
         setupVideoOutput();
     }
+#else
+    Q_UNUSED(movie);
 #endif
 }