adapting comment to new implementation

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@37120 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/mac/carbon/bitmap.h

@@ -46,7 +46,7 @@ public:
     // Construct a mask from a mono bitmap (black meaning show pixels, white meaning transparent)
     wxMask(const wxBitmap& bitmap);
     
-    // implementation helper only : construct a mask from a 8 bit memory buffer
+    // implementation helper only : construct a mask from a 32 bit memory buffer
     wxMask(const wxMemoryBuffer& buf, int width , int height , int bytesPerRow ) ;
 
     ~wxMask();