sdio_uart: Fix SDIO break control to now return success or an error

This is a consequence of patch 9ea761bfef52c116fed4715d4043392c2503fe6a.

Signed-off-by: David Howells <[e-mail]>
Signed-off-by: Pierre Ossman <[e-mail]>

drivers/mmc/card/sdio_uart.c

···
 	sdio_uart_release_func(port);
 }
 
-static void sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
+static int sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
 {
 	struct sdio_uart_port *port = tty->driver_data;
+	int result;
 
-	if (sdio_uart_claim_func(port) != 0)
-		return;
+	result = sdio_uart_claim_func(port);
+	if (result != 0)
+		return result;
 
 	if (break_state == -1)
 		port->lcr |= UART_LCR_SBC;
···
 	sdio_out(port, UART_LCR, port->lcr);
 
 	sdio_uart_release_func(port);
+	return 0;
 }
 
 static int sdio_uart_tiocmget(struct tty_struct *tty, struct file *file)