[SERIAL] Fix typo in comment

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

drivers/serial/8250.c

@@ -2198,7 +2198,7 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
 	touch_nmi_watchdog();
 
 	/*
-	 *	First save the UER then disable the interrupts
+	 *	First save the IER then disable the interrupts
 	 */
 	ier = serial_in(up, UART_IER);