push tests: deeply free the push status

Don't just free the push status structure, actually free the strings that were
strdup'd into the struct as well.

(cherry picked from commit dad99881)

tests/online/push.c

@@ -152,8 +152,12 @@ static void do_verify_push_status(record_callbacks_data *data, const push_status
 		git_buf_free(&msg);
 	}
 
-	git_vector_foreach(actual, i, iter)
-		git__free(iter);
+	git_vector_foreach(actual, i, iter) {
+		push_status *s = (push_status *)iter;
+		git__free(s->ref);
+		git__free(s->msg);
+		git__free(s);
+	}
 
 	git_vector_free(actual);
 }