linux-phytec-ti

USB: cdc-acm: fix potential null-pointer dereference

Must check return value of tty_port_tty_get.

Cc: stable <stable@kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>