winebuild: Cast-qual warnings fix

[Andrew Talbot]

Changelog:
    winebuild: Cast-qual warnings fix.

diff -urN a/tools/winebuild/res16.c b/tools/winebuild/res16.c
--- a/tools/winebuild/res16.c	2006-08-12 15:57:25.000000000 +0100
+++ b/tools/winebuild/res16.c	2006-08-22 23:14:52.000000000 +0100
@@ -142,7 +142,7 @@
     }
     else
     {
-        char *p = xmalloc( (strlen((char*)file_pos) + 1) );
+        char *p = xmalloc(strlen((const char *)file_pos) + 1);
         str->str = p;
         str->id = 0;
         while ((*p++ = get_byte()));