pinctrl: single: fix refcount leak in pcs_add_gpio_func()

of_parse_phandle_with_args() returns a device_node pointer with refcount
incremented in gpiospec.np. The loop iterates through all phandles but
never releases the reference, causing a refcount leak on each iteration.

Add of_node_put() calls to release the reference after extracting the
needed arguments and on the error path when devm_kzalloc() fails.

This bug was detected by our static analysis tool and verified by my
code review.

Fixes: a1a277eb76b3 ("pinctrl: single: create new gpio function range")
Signed-off-by: Wei Li <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/pinctrl-single.c

···
 		}
 		range = devm_kzalloc(pcs->dev, sizeof(*range), GFP_KERNEL);
 		if (!range) {
+			of_node_put(gpiospec.np);
 			ret = -ENOMEM;
 			break;
 		}
···
 		mutex_lock(&pcs->mutex);
 		list_add_tail(&range->node, &pcs->gpiofuncs);
 		mutex_unlock(&pcs->mutex);
+		of_node_put(gpiospec.np);
 	}
 	return ret;
 }