virfirewalltest: Don't duplicate string when adding it onto stringlist

In our wrapper of g_dbus_connection_call_sync() in
virfirewalltest a string is duplicated and added onto a
virStringList. This leads to a memory leak because
virStringListAdd() duplicates the string itself.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>

tests/virfirewalltest.c

@@ -122,7 +122,7 @@ VIR_MOCK_WRAP_RET_ARGS(g_dbus_connection_call_sync,
                 doError = true;
             }
 
-            virStringListAdd(&args, g_strdup(item));
+            virStringListAdd(&args, item);
         }
 
         if (fwBuf) {