[janitor] dlls/cabinet -Wwrite-strings cleanup

[Daniel Marmier <d.marmier@bluewin.ch>]

Fixed warnings with gcc option "-Wwrite-strings".

Index: dlls/cabinet/cabextract.c
===================================================================
RCS file: /home/wine/wine/dlls/cabinet/cabextract.c,v
retrieving revision 1.9
diff -u -r1.9 cabextract.c
--- dlls/cabinet/cabextract.c	5 Sep 2003 23:08:44 -0000	1.9
+++ dlls/cabinet/cabextract.c	6 Oct 2003 20:21:06 -0000
@@ -2486,7 +2486,8 @@
 
 exit_handler:
   if (err) {
-    char *errmsg, *cabname;
+    const char *errmsg;
+    char *cabname;
     switch (err) {
     case DECR_NOMEMORY:
       errmsg = "out of memory!\n"; break;