The test cases ap_ht40_5ghz_invalid_pair and ap_ht40_5ghz_disabled_sec
mixed use of apdev[0] and apdev[1] while only needing a single AP. This
works when both the devices are on the same host (e.g., with
mac80211_hwsim), but not when using separate remote hosts. Fix this by
using apdev[0] more consistently in these test cases.
Signed-off-by: Jonathan Afek <jonathanx.afek@intel.com>