USB: ssu100: fix overrun-error reporting

commit 75bcbf29 upstream.

Fix reporting of overrun errors, which should only be reported once
using the inserted null character.

Fixes: 6b8f1ca5 ("USB: ssu100: set tty_flags in ssu100_process_packet")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/usb/serial/ssu100.c

@@ -490,10 +490,9 @@ static void ssu100_update_lsr(struct usb_serial_port *port, u8 lsr,
 			if (*tty_flag == TTY_NORMAL)
 				*tty_flag = TTY_FRAME;
 		}
-		if (lsr & UART_LSR_OE){
+		if (lsr & UART_LSR_OE) {
 			port->icount.overrun++;
-			if (*tty_flag == TTY_NORMAL)
-				*tty_flag = TTY_OVERRUN;
+			tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
 		}
 	}
 
@@ -511,12 +510,8 @@ static void ssu100_process_read_urb(struct urb *urb)
 	if ((len >= 4) &&
 	    (packet[0] == 0x1b) && (packet[1] == 0x1b) &&
 	    ((packet[2] == 0x00) || (packet[2] == 0x01))) {
-		if (packet[2] == 0x00) {
+		if (packet[2] == 0x00)
 			ssu100_update_lsr(port, packet[3], &flag);
-			if (flag == TTY_OVERRUN)
-				tty_insert_flip_char(&port->port, 0,
-						TTY_OVERRUN);
-		}
 		if (packet[2] == 0x01)
 			ssu100_update_msr(port, packet[3]);