auto-t: fix hotspot tests to remove main.conf

The hotspot tests were not cleaning up /tmp/main.conf, which resulted
in future tests failing.

autotests/testHotspot/hessid_test.py

@@ -64,6 +64,7 @@ class Test(unittest.TestCase):
     @classmethod
     def tearDownClass(cls):
         IWD.clear_storage()
+        os.remove('/tmp/main.conf')
 
 if __name__ == '__main__':
     unittest.main(exit=True)

autotests/testHotspot/hotspot_test.py

@@ -64,6 +64,7 @@ class Test(unittest.TestCase):
     @classmethod
     def tearDownClass(cls):
         IWD.clear_storage()
+        os.remove('/tmp/main.conf')
 
 if __name__ == '__main__':
     unittest.main(exit=True)

autotests/testHotspot/roaming_test.py

@@ -64,6 +64,7 @@ class Test(unittest.TestCase):
     @classmethod
     def tearDownClass(cls):
         IWD.clear_storage()
+        os.remove('/tmp/main.conf')
 
 if __name__ == '__main__':
     unittest.main(exit=True)