bcachefs: Fix stripe create error path

If we errored out on a new stripe before fully allocating it, we
shouldn't be zeroing out unwritten data.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/ec.c

@@ -1078,6 +1078,7 @@ static void ec_stripe_create(struct ec_stripe_new *s)
 
 	closure_sync(&s->iodone);
 
+	if (!s->err) {
 		for (i = 0; i < nr_data; i++)
 			if (s->blocks[i]) {
 				ob = c->open_buckets + s->blocks[i];
@@ -1085,6 +1086,7 @@ static void ec_stripe_create(struct ec_stripe_new *s)
 				if (ob->sectors_free)
 					zero_out_rest_of_ec_bucket(c, s, i, ob);
 			}
+	}
 
 	if (s->err) {
 		if (!bch2_err_matches(s->err, EROFS))