tty: Remove lots of NULL checks

Many tty drivers contain 'can't happen' checks against NULL pointers passed
in by the tty layer. These have never been possible to occur. Even more
importantly if they ever do occur we want to know as it would be a serious
bug.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/mxser.c

@@ -616,9 +616,6 @@ static int mxser_set_baud(struct tty_struct *tty, long newspd)
 	int quot = 0, baud;
 	unsigned char cval;
 
-	if (!tty->termios)
-		return -1;
-
 	if (!info->ioaddr)
 		return -1;
 
@@ -688,8 +685,6 @@ static int mxser_change_speed(struct tty_struct *tty,
 	int ret = 0;
 	unsigned char status;
 
-	if (!tty->termios)
-		return ret;
 	cflag = tty->termios->c_cflag;
 	if (!info->ioaddr)
 		return ret;