nvmem: fix memory leak in error path

We need to free the ida mapping and nvmem struct if the write-protect
GPIO lookup fails.

Fixes: 2a127da4 ("nvmem: add support for the write-protect pin")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200310132257.23358-7-srinivas.kandagatla@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/nvmem/core.c

@@ -353,8 +353,12 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	else
 		nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
 						    GPIOD_OUT_HIGH);
-	if (IS_ERR(nvmem->wp_gpio))
-		return ERR_CAST(nvmem->wp_gpio);
+	if (IS_ERR(nvmem->wp_gpio)) {
+		ida_simple_remove(&nvmem_ida, nvmem->id);
+		rval = PTR_ERR(nvmem->wp_gpio);
+		kfree(nvmem);
+		return ERR_PTR(rval);
+	}
 
 	kref_init(&nvmem->refcnt);
 	INIT_LIST_HEAD(&nvmem->cells);