ppc/spapr_drc: fix memory leak

fix CID 1311373.
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Message-Id: <1436489490-236-3-git-send-email-arei.gonglei@huawei.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/ppc/spapr_drc.c

@@ -422,6 +422,7 @@ static void realize(DeviceState *d, Error **errp)
         error_free(err);
         object_unref(OBJECT(drc));
     }
+    g_free(child_name);
     DPRINTFN("drc realize complete");
 }