Fix typo

Change-Id: Iff7717094f82fdbb13b09c05cb44d059c7ba5f3b
Reviewed-on: https://gerrit.libreoffice.org/64575
Tested-by: Jenkins
Reviewed-by: Julien Nabet <serval2412@yahoo.fr>

canvas/source/directx/dx_spritecanvashelper.cxx

@@ -158,7 +158,7 @@ namespace dxcanvas
         // clear area that needs to be blitted to screen beforehand
         maUpdateRect.reset();
 
-        // TODO(P1): Might be worthwile to track areas of background
+        // TODO(P1): Might be worthwhile to track areas of background
         // changes, too.
 
         // TODO(P2): Might be worthwhile to use page-flipping only if