USB: digi_acceleport: fix port-data memory leak

USB: digi_acceleport: fix port-data memory leak

commit fb44ff854e148bc5c5982dad32da98b7a0989d2d upstream.

Fix port-data memory leak by moving port data allocation and
deallocation to port_probe and port_remove.

Since commit 0998d0631001288 (device-core: Ensure drvdata = NULL when no
driver is bound) the port private data is no longer freed at release as
it is no longer accessible.

Note that the oob port is never registered as a port device and should
thus be handled in attach and release.

Compile-only tested.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: Peter Berger <pberger@brimson.com>
Cc: Al Borchers <alborchers@steinerpoint.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>