staging: vt6656: Fix pairwise key entry save.

staging: vt6656: Fix pairwise key entry save.

The problem is that the group key was saved as VNT_KEY_DEFAULTKEY
was over written by the VNT_KEY_GROUP_ADDRESS index.

mac80211 could not clear the mac_addr in the default key.

The VNT_KEY_DEFAULTKEY is not necesscary so remove it and set as
VNT_KEY_GROUP_ADDRESS.

mac80211 can clear any key using vnt_mac_disable_keyentry.

Fixes: c6ccaa907a3a ("staging: vt6656: Fix pairwise key for non station modes")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Link: https://lore.kernel.org/r/da2f7e7f-1658-1320-6eee-0f55770ca391@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>