Fix annoying warning in qtxmlpatterns about a value too big for the enum

api/qcoloroutput_p.h:74:60: error: signed shift result (0xFFFFF00000) requires 41 bits to represent, but 'int' only has 32 bits [-Werror,-Wshift-overflow]

The masks don't look right anyway. Let's just hardcode them according
to how many colours are used.

Change-Id: Idd3438ecab3fb666bd84929fb731011224b9c68e
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

src/xmlpatterns/api/qcoloroutput_p.h

@@ -70,8 +70,8 @@ namespace QPatternist
             ForegroundShift = 10,
             BackgroundShift = 20,
             SpecialShift    = 20,
-            ForegroundMask  = ((1 << ForegroundShift) - 1) << ForegroundShift,
-            BackgroundMask  = ((1 << BackgroundShift) - 1) << BackgroundShift
+            ForegroundMask  = 0x1f << ForegroundShift,
+            BackgroundMask  = 0x7 << BackgroundShift
         };
 
     public: