mac80211: fix bad guard when reporting legacy rates

mac80211: fix bad guard when reporting legacy rates

When reporting legacy rates inside the TX Radiotap header we need to split
the check between "uses tx_statua_ext" and "is legacy rate". Not doing so
would make the code drop into the !tx_status_ext path.

Fixes: 3d07ffcaf320 ("mac80211: add struct ieee80211_tx_status support to ieee80211_add_tx_radiotap_header")
Signed-off-by: John Crispin <john@phrozen.org>
Link: https://lore.kernel.org/r/20190807075949.32414-2-john@phrozen.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>