wifi: mt76: mt7925: fix AMPDU state handling in mt7925_tx_check_aggr

wifi: mt76: mt7925: fix AMPDU state handling in mt7925_tx_check_aggr

Previously, the AMPDU state bit for a given TID was set before attempting
to start a BA session, which could result in the AMPDU state being marked
active even if ieee80211_start_tx_ba_session() failed. This patch changes
the logic to only set the AMPDU state bit after successfully starting a BA
session, ensuring proper synchronization between AMPDU state and BA session
status.

This fixes potential issues with aggregation state tracking and improves
compatibility with mac80211 BA session management.

Fixes: 44eb173bdd4f ("wifi: mt76: mt7925: add link handling in mt7925_txwi_free")
Cc: stable@vger.kernel.org
Signed-off-by: Quan Zhou <quan.zhou@mediatek.com>
Reviewed-by: Sean Wang <sean.wang@mediatek.com>
Link: https://patch.msgid.link/d5960fbced0beaf33c30203f7f8fb91d0899c87b.1764228973.git.quan.zhou@mediatek.com
Signed-off-by: Felix Fietkau <nbd@nbd.name>