Fix tor-fw-helper exit code.

It's returning the number of initialized backends.

(changes file added by nickm; this is a fix for bug #9030)

changes/bug9030

@@ -0,0 +1,4 @@
+  o Minor bugfixes:
+    - The tor-fw-helper program now follows the standard convention and
+      exits with status code "0" on success. Fixes bug 9030; bugfix on
+      0.2.3.1-alpha. Patch by Arlo Breault.

src/tools/tor-fw-helper/tor-fw-helper.c

@@ -496,6 +496,6 @@ main(int argc, char **argv)
     smartlist_free(tor_fw_options.ports_to_forward);
   }
 
-  exit(r);
+  exit(0);
 }