mac80211: never drop injected frames even if normally not allowed

In ieee80211_tx_dequeue there is a check to see if the dequeued frame
is allowed in the current state. Injected frames that are normally
not allowed are being be dropped here. Fix this by checking if a
frame was injected and if so always allowing it.

Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
Link: https://lore.kernel.org/r/20200723100153.31631-1-Mathy.Vanhoef@kuleuven.be


Signed-off-by: Johannes Berg <johannes.berg@intel.com>