Initialize mt76_txq pointer after ieee80211_txq pointer check.
Remove space after the pointer cast

Fixes: 7bc04215 ("mt76: add driver code for MT76x2e")
Signed-off-by: NLorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>