tests: Make WPA2-Enterprise reauth test cases more robust

tests: Make WPA2-Enterprise reauth test cases more robust

With the extra latencies removed from run-tests.py operations, it was
possible to hit race conditions in pairwise cipher configuration at the
end of the 4-way handshake. In some cases, the EAPOL-Start frame from
the station was not received by the AP and that could result in these
test cases failing. Since there are not really trying to test the race
condition, wait for the AP side to complete key configuration prior to
initiating the reauthentication sequence.

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