n_tty: Special case EXTPROC receive_buf() as raw mode

When EXTPROC is set without ISTRIP or IUCLC, processing is
identical to raw mode; handle this receiving mode as a special-case
of raw mode.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/n_tty.c

@@ -1546,10 +1546,11 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
 			  char *fp, int count)
 {
 	struct n_tty_data *ldata = tty->disc_data;
+	bool preops = I_ISTRIP(tty) || (I_IUCLC(tty) && L_IEXTEN(tty));
 
 	if (ldata->real_raw)
 		n_tty_receive_buf_real_raw(tty, cp, fp, count);
-	else if (ldata->raw)
+	else if (ldata->raw || (L_EXTPROC(tty) && !preops))
 		n_tty_receive_buf_raw(tty, cp, fp, count);
 	else {
 		char flag = TTY_NORMAL;