gdkdevicemanager-win32.c: Fix build

Fix the call to p_WTSetA, as we should be passing in a HCTX, not a
HCTX*.  Also clean up things a bit.

gdk/win32/gdkdevicemanager-win32.c

@@ -1148,15 +1148,10 @@ wintab_init_check (GdkDeviceManagerWin32 *device_manager)
       if (!(lc.lcOptions & CXO_SYSTEM))
         {
           lc.lcOptions |= CXO_SYSTEM;
-          if (!p_WTSetA (hctx, &lc))
-            {
+          if (!p_WTSetA (*hctx, &lc))
             g_warning ("Could not set the CXO_SYSTEM option in the WINTAB context");
         }
-        }
 
-#if 0
-      (*p_WTEnable) (*hctx, TRUE);
-#endif
       (*p_WTOverlap) (*hctx, TRUE);
 
 #if DEBUG_WINTAB