tty: 8250, cleanup em485 timers

Initialize the variables directly by initializers in definitions. This
is expected/usual for these kind of callback.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-12-jslaby@suse.cz


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>