mailbox: Remove unneeded semicolon

Remove unnecessary semicolons reported by Coccinelle/coccicheck and the
semantic patch at scripts/coccinelle/misc/semicolon.cocci.

Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

Author: Chen Ni

drivers/mailbox/exynos-mailbox.c

@@ -57,7 +57,7 @@ static int exynos_mbox_send_data(struct mbox_chan *chan, void *data)
 	if (msg->chan_type != EXYNOS_MBOX_CHAN_TYPE_DOORBELL) {
 		dev_err(dev, "Unsupported channel type [%d]\n", msg->chan_type);
 		return -EINVAL;
-	};
+	}
 
 	writel(BIT(msg->chan_id), exynos_mbox->regs + EXYNOS_MBOX_INTGR1);