USB: serial: kobil_sct: log failure to update line settings

Log failure to update the line settings in set_termios().

This also avoids a W=1 (-Wunused-but-set-variable) warning.

Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Signed-off-by: Johan Hovold <[e-mail]>

drivers/usb/serial/kobil_sct.c

···
 		  0,
 		  KOBIL_TIMEOUT
 		);
+	if (result) {
+		dev_err(&port->dev, "failed to update line settings: %d\n",
+				result);
+	}
 }
 
 static int kobil_ioctl(struct tty_struct *tty,