tests: Fix the file comment to describe what this script does

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

tests/hwsim/run-tests.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 #
-# AP tests
+# Test case executor
 # Copyright (c) 2013-2014, Jouni Malinen <j@w1.fi>
 #
 # This software may be distributed under the terms of the BSD license.