macosx: NSScreen(VLCAdditions) does not leak.

The Objective-C runtime will properly unload this at the end of the application. The mozilla plugin should not even be using this at all.
(cherry picked from commit 573844a9)
Signed-off-by: Derk-Jan Hartman <hartman@videolan.org>

modules/gui/macosx/misc.m

@@ -132,13 +132,6 @@ static NSMutableArray *blackoutWindows = nil;
     blackoutWindows = [[NSMutableArray alloc] initWithCapacity:1];
 }
 
-- (void)dealloc
-{
-    [blackoutWindows removeAllObjects];
-    [blackoutWindows release];
-    [super dealloc];
-}
-
 + (NSScreen *)screenWithDisplayID: (CGDirectDisplayID)displayID
 {
     int i;