gdi32/tests: Cast-qual warning fix

[Andrew Talbot]

Changelog:
    gdi32/tests: Cast-qual warning fix.

diff -urN a/dlls/gdi32/tests/metafile.c b/dlls/gdi32/tests/metafile.c
--- a/dlls/gdi32/tests/metafile.c	2006-10-20 14:01:36.000000000 +0100
+++ b/dlls/gdi32/tests/metafile.c	2006-12-08 21:57:37.000000000 +0000
@@ -280,7 +280,7 @@
 
     case EMR_RESTOREDC:
         {
-            EMRRESTOREDC *restoredc = (EMRRESTOREDC *)emr;
+            const EMRRESTOREDC *restoredc = (const EMRRESTOREDC *)emr;
             switch(++restore_no)
             {
             case 1: