tests: Make ap_vlan_wpa2_radius_id_change more robust

Wait for the 4-way handshake completion instead of assuming it gets done
in 0.1 seconds.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
diff --git a/tests/hwsim/test_ap_vlan.py b/tests/hwsim/test_ap_vlan.py
index cd45297..7b10ea7 100644
--- a/tests/hwsim/test_ap_vlan.py
+++ b/tests/hwsim/test_ap_vlan.py
@@ -113,7 +113,9 @@
     ev = dev[0].wait_event(["CTRL-EVENT-EAP-SUCCESS"], timeout=15)
     if ev is None:
         raise Exception("EAP reauthentication timed out")
-    time.sleep(0.1)
+    ev = dev[0].wait_event(["WPA: Key negotiation completed"], timeout=5)
+    if ev is None:
+        raise Exception("4-way handshake after reauthentication timed out")
     state = dev[0].get_status_field('wpa_state')
     if state != "COMPLETED":
         raise Exception("Unexpected state after reauth: " + state)