tests: Make scan_random_mac more robust

There is a race condition between wlantest having received and written
the sniffer log and this test case using tshark to process it. Wait one
second before running tshark to make it less likely to get truncated
results that can result in the test case failing.

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

tests/hwsim/test_scan.py

@@ -707,6 +707,9 @@ def _test_scan_random_mac(dev, apdev, params):
     for args in tests:
         dev[0].request("MAC_RAND_SCAN " + args)
         dev[0].scan_for_bss(bssid, freq=2412, force_scan=True)
+    # wait a bit to make it more likely for wlantest sniffer to have captured
+    # and written the results into a file that we can process here
+    time.sleep(1)
 
     try:
         arg = [ "tshark",