win32ole.c: suppress a warning

* ext/win32ole/win32ole.c (ole_vstr2wc): downcast to suppress a
  warning.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42663 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/win32ole/win32ole.c

@@ -1311,7 +1311,7 @@ ole_vstr2wc(VALUE vstr)
     enc = rb_enc_get(vstr);
 
     if (st_lookup(enc2cp_table, (st_data_t)enc, &data)) {
-        cp = data;
+        cp = (int)data;
     } else {
         cp = ole_encoding2cp(enc);
         if (code_page_installed(cp) ||