qt: drop legacy NSAutoreleasePool pattern

modules/gui/qt4/util/searchlineedit_mac.mm

@@ -41,8 +41,7 @@ SearchLineEdit::SearchLineEdit(QWidget *parent)
 {
     // Many Cocoa objects create temporary autorelease objects,
     // so create a pool to catch them.
-    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
-
+    @autoreleasepool {
         // Create the NSSearchField, set it on the QCocoaViewContainer.
         NSSearchField *search = [[NSSearchField alloc] init];
         setCocoaView(search);
@@ -55,9 +54,7 @@ SearchLineEdit::SearchLineEdit(QWidget *parent)
         // Release our reference, since our super class takes ownership and we
         // don't need it anymore.
         [search release];
-
-    // Clean up our pool as we no longer need it.
-    [pool release];
+    }
 }
 //![0]