staging: rtl8723au: Get rid of second set of custom error codes

One set of custom error codes for the driver should more than
suffice. This allows us to get rid of odm_types.h as well.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>