tests: Fix regulatory domain reset in FST test case failure cases

send_iface_detach_request() can fail and that resulted in skipping a
call to restore_reg_domain() and leaving unexpected country
configuration for following test cases. This could result in failures,
e.g., in this sequence: fst_proto wpas_mesh_open_5ghz

Fix this by ignoring exceptions from send_iface_detach_request() and
continuing to restore regulatory domain.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

tests/hwsim/fst_module_aux.py

@@ -621,7 +621,10 @@ class FstAP (FstDevice):
         hostapd."""
         if len(self.fst_group) != 0:
             self.remove_all_sessions()
-            self.send_iface_detach_request(self.iface)
+            try:
+                self.send_iface_detach_request(self.iface)
+            except Exception, e:
+                logger.info(str(e))
         self.reg_ctrl.stop()
         del self.global_instance
         self.global_instance = None