This reverts commit 
eba0e3c3a0ba7b96f01cbe997680f6a4401a0bfc.
When merged together (usb-linus and usb-next), this fix isn't needed and
causes a build error.  Revert the commit to solve the build issue.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
                port->port.ops = &serial_port_ops;
                port->serial = serial;
                spin_lock_init(&port->lock);
-               init_waitqueue_head(&port->delta_msr_wait);
                /* Keep this for private driver use for the moment but
                   should probably go away */
                INIT_WORK(&port->work, usb_serial_port_work);