staging: vt6656: Remove unused variable bLongHeader

Remove dead bLongHeader code.

In s_vFillTxKey use ieee80211_has_a4 to detect long headers for future use.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>