tty_wakeup is safe to be called from all contexts. No need to schedule
a work for that. Let us call it directly like in other drivers.

This allows us to kill another member of rfcomm_dev structure.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>