tests: Make ap_mixed_security more robust

This test case uses get_bss() with a BSSID to find a BSS entry. That can
result in failures if there are multiple BSS entries in wpa_supplicant
BSS table for the same BSSID, e.g., due to an earlier hidden SSID test
case. Explicitly clear the cfg80211 and wpa_supplicant scan caches at
the beginning of this test case to make it less likely for earlier test
cases to trigger a failure here.

Signed-off-by: Jouni Malinen <j@w1.fi>

tests/hwsim/test_ap_mixed.py

@@ -12,6 +12,7 @@ import hwsim_utils
 
 def test_ap_mixed_security(dev, apdev):
     """WPA/WPA2 with PSK, EAP, SAE, FT in a single BSS"""
+    dev[0].flush_scan_cache()
     sae = "SAE" in dev[0].get_capability("auth_alg")
     ssid = "test-mixed"
     passphrase = 'qwertyuiop'