ar71xx: Fix mikrotik NAND compile problem

There is one closing bracket too much.

Fixes: 9cad70044f ("kernel: fix nand_release() usage.")
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
(cherry picked from commit 014d3f593acea13ee6aa002d858f182806ed43f0)

target/linux/ar71xx/files/drivers/mtd/nand/rb4xx_nand.c

@@ -356,7 +356,7 @@ static int rb4xx_nand_remove(struct platform_device *pdev)
 {
 	struct rb4xx_nand_info *info = platform_get_drvdata(pdev);
 
-	nand_release(&info->chip));
+	nand_release(&info->chip);
 	platform_set_drvdata(pdev, NULL);
 	kfree(info);
 	gpio_free(RB4XX_NAND_GPIO_NCE);