tty: update obsolete termios comment

Update an obsolete comment referring to the termios_locked structure
which was removed over a decade ago by commit fe6e29fdb1a7 ("tty:
simplify ktermios allocation").

While at it, fix the "Thus" typo.

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

drivers/tty/tty_io.c

···
  *	tty_init_termios	-  helper for termios setup
  *	@tty: the tty to set up
  *
- *	Initialise the termios structures for this tty. Thus runs under
+ *	Initialise the termios structure for this tty. This runs under
  *	the tty_mutex currently so we can be relaxed about ordering.
  */