reset: Do not register resource data for missing resets

When an optional reset is not present, __devm_reset_control_get() and
devm_reset_control_array_get() still register resource data to release
the non-existing reset on cleanup, which is futile.

Fix this by skipping NULL reset control pointers.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/reset/core.c

@@ -787,7 +787,7 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
 		return ERR_PTR(-ENOMEM);
 
 	rstc = __reset_control_get(dev, id, index, shared, optional, acquired);
-	if (!IS_ERR(rstc)) {
+	if (!IS_ERR_OR_NULL(rstc)) {
 		*ptr = rstc;
 		devres_add(dev, ptr);
 	} else {
@@ -928,7 +928,7 @@ devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
 		return ERR_PTR(-ENOMEM);
 
 	rstc = of_reset_control_array_get(dev->of_node, shared, optional, true);
-	if (IS_ERR(rstc)) {
+	if (IS_ERR_OR_NULL(rstc)) {
 		devres_free(devres);
 		return rstc;
 	}