test_objagg: Uninitialized variable in error handling

We need to set the error message on this path otherwise some of the
callers, such as test_hints_case(), print from an uninitialized pointer.

We had a similar bug earlier and set "errmsg" to NULL in the caller,
test_delta_action_item().  That code is no longer required so I have
removed it.

Fixes: 9069a381 ("lib: objagg: implement optimization hints assembly and use hints for object creation")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

lib/test_objagg.c

@@ -745,8 +745,10 @@ static int check_expect_stats(struct objagg *objagg,
 	int err;
 
 	stats = objagg_stats_get(objagg);
-	if (IS_ERR(stats))
+	if (IS_ERR(stats)) {
+		*errmsg = "objagg_stats_get() failed.";
 		return PTR_ERR(stats);
+	}
 	err = __check_expect_stats(stats, expect_stats, errmsg);
 	objagg_stats_put(stats);
 	return err;
@@ -786,7 +788,6 @@ static int test_delta_action_item(struct world *world,
 	if (err)
 		goto errout;
 
-	errmsg = NULL;
 	err = check_expect_stats(objagg, &action_item->expect_stats, &errmsg);
 	if (err) {
 		pr_err("Key %u: Stats: %s\n", action_item->key_id, errmsg);