QNSColorPanelDelegate: Don't restore stolen view on dealloc

We may not be playing nice with Cocoa's internals when
we decide to reparent NSColorPanel's contents to add
QColorDialog's own OK/Cancel buttons. In order to reduce
issues, we should avoid poking at things during the
application's shutdown sequence. Simply releasing the
stolen view should be enough at that point.

A similar pattern exists in QNSFontPanelDelegate.

Change-Id: I678c236e0c57c4d08a1109a479d965f924288c54
Task-number: QTBUG-56448
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@theqtcompany.com>
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>

src/plugins/platforms/cocoa/qcocoacolordialoghelper.mm

@@ -116,7 +116,7 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSColorPanelDelegate);
 
 - (void)dealloc
 {
-    [self restoreOriginalContentView];
+    [mStolenContentView release];
     [mColorPanel setDelegate:nil];
     [[NSNotificationCenter defaultCenter] removeObserver:self];
 

src/plugins/platforms/cocoa/qcocoafontdialoghelper.mm

@@ -144,7 +144,7 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSFontPanelDelegate);
 
 - (void)dealloc
 {
-    [self restoreOriginalContentView];
+    [mStolenContentView release];
     [mFontPanel setDelegate:nil];
     [[NSFontManager sharedFontManager] setDelegate:nil];
     [[NSNotificationCenter defaultCenter] removeObserver:self];