Fix validation of EAPOL-Key length with AES key wrap (CID 62859)

Fix validation of EAPOL-Key length with AES key wrap (CID 62859)

The additional eight octet field was removed from keydatalen without
proper validation of the Key Data Length field. It would have been
possible for an invalid EAPOL-Key frame to be processed in a way that
ends up reading beyond the buffer. In theory, this could have also
resulted in writing beyond the EAPOL-Key frame buffer, but that is
unlikely to be feasible due to the AES key wrap validation step on
arbitrary memory contents.

Signed-off-by: Jouni Malinen <j@w1.fi>