mt76: do not store aggregation sequence number for null-data frames

Fixes a rare corner case where a BlockAckReq might get the wrong
sequence number.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Felix Fietkau 2018-10-08 10:39:24 +02:00
commit 5155938d8a