dlltool: replace unchecked malloc with xmalloc

binutils/dlltool.c

@@ -876,7 +876,7 @@ dlltmp (char **buf, const char *fmt)
 {
   if (!*buf)
     {
-      *buf = malloc (strlen (tmp_prefix) + 64);
+      *buf = xmalloc (strlen (tmp_prefix) + 64);
       sprintf (*buf, fmt, tmp_prefix);
     }
   return *buf;