serial: bfin_5xx: fix typo in IER check

This most likely won't cause problems on systems as people don't typically
enable GPIO RTS/CTS if they don't actually use it.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/serial/bfin_5xx.c

@@ -797,7 +797,7 @@ static void bfin_serial_shutdown(struct uart_port *port)
 		gpio_free(uart->rts_pin);
 #endif
 #ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
-	if (UART_GET_IER(uart) && EDSSI)
+	if (UART_GET_IER(uart) & EDSSI)
 		free_irq(uart->status_irq, uart);
 #endif
 }