staging: rtl8723au: Eliminate RTW_STATUS_CODE23a()

Inline the parsing of status codes. Long term we should pass back the
proper status codes and get rid of the ugly _FAIL/_SUCCESS mess. This
is one small step in that direction.

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