tty_ioctl, little whitespace cleanup

the point is to make
while (++i < n_baud_table);
clear and assign it to the do { } loop
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>