regulator: of: fix a NULL vs IS_ERR() check in of_regulator_bulk_get_all()

The regulator_get() function never returns NULL. It returns error pointers.

Fixes: 27b9ecc7 ("regulator: Add of_regulator_bulk_get_all")
Signed-off-by: Peng Wu <wupeng58@huawei.com>
Link: https://lore.kernel.org/r/20221122082242.82937-1-wupeng58@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/of_regulator.c

@@ -767,7 +767,7 @@ int of_regulator_bulk_get_all(struct device *dev, struct device_node *np,
 			memcpy(name, prop->name, i);
 			name[i] = '\0';
 			tmp = regulator_get(dev, name);
-			if (!tmp) {
+			if (IS_ERR(tmp)) {
 				ret = -EINVAL;
 				goto error;
 			}