When .release_buffered_frames was implemented, only A-MPDU packets were
buffered internally. Now that this has changed, the BUF_AMPDU flag needs
to be checked before calling ath_tx_addto_baw
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>