mac80211: fix AP mode EAP tx for VLAN stations

mac80211: fix AP mode EAP tx for VLAN stations

commit 66f2c99af3d6f2d0aa1120884cf1c60613ef61c0 upstream.

EAP frames for stations in an AP VLAN are sent on the main AP interface
to avoid race conditions wrt. moving stations.
For that to work properly, sta_info_get_bss must be used instead of
sta_info_get when sending EAP packets.
Previously this was only done for cooked monitor injected packets, so
this patch adds a check for tx->skb->protocol to the same place.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>