Fixed warning with Xcode 7.3.0
diff --git a/src/video/cocoa/SDL_cocoawindow.m b/src/video/cocoa/SDL_cocoawindow.m
index 4ada9f1..a1f93a5 100644
--- a/src/video/cocoa/SDL_cocoawindow.m
+++ b/src/video/cocoa/SDL_cocoawindow.m
@@ -1158,7 +1158,7 @@
     }
 
     {
-        unsigned int style = [nswindow styleMask];
+        unsigned long style = [nswindow styleMask];
 
         if (style == NSBorderlessWindowMask) {
             window->flags |= SDL_WINDOW_BORDERLESS;