commit ed797074 upstream.

We should stop I/O unconditionally at suspend rather than rely on the
tty-port initialised flag (which is set prior to stopping I/O during
shutdown) in order to prevent suspend returning with URBs still active.

Fixes: 11ea859d ("USB: additional power savings for cdc-acm devices
that support remote wakeup")
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>