fix lit tests

artiq/test/lit/lit.cfg

@@ -11,6 +11,7 @@ root = os.path.join(os.path.dirname(__file__), "..")
 config.name = "ARTIQ"
 config.test_format = lit.formats.ShTest()
 config.suffixes = [".py"]
+config.excludes = ["not.py", "device_db.py"]
 
 if os.getenv("COVERAGE"):
     config.environment["COVERAGE_FILE"] = os.path.join(root, "..", ".coverage")
@@ -22,7 +23,7 @@ config.substitutions.append( ("%python", python) )
 if os.getenv("PYTHONPATH"):
     config.environment["PYTHONPATH"] = os.getenv("PYTHONPATH")
 
-not_ = "{} {}".format(sys.executable, os.path.join(root, "not.py"))
+not_ = "{} {}".format(sys.executable, os.path.join(root, "lit", "not.py"))
 config.substitutions.append( ("%not", not_) )
 
 if os.name == "posix":