QPainter: use qDeleteAll()

Change-Id: I167e4d7a57e92eb5ea7c39b04246ac2f44c91de0
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

src/gui/painting/qpainter.cpp

@@ -208,8 +208,7 @@ void QPainterPrivate::checkEmulation()
 QPainterPrivate::~QPainterPrivate()
 {
     delete emulationEngine;
-    for (int i=0; i<states.size(); ++i)
-        delete states.at(i);
+    qDeleteAll(states);
 
     if (dummyState)
         delete dummyState;