mrhlpr, mrtest: Simplify call to main()

frontend.main() only ever returns None, so there's no point in
calling sys.exit with its return value as parameter.

mrhlpr.py

@@ -3,8 +3,7 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 # PYTHON_ARGCOMPLETE_OK
 
-import sys
 import mrhlpr.frontend
 
 if __name__ == "__main__":
-    sys.exit(mrhlpr.frontend.main())
+    mrhlpr.frontend.main()

mrhlpr/frontend.py

@@ -254,7 +254,7 @@ def parse_args() -> argparse.Namespace:
     return parser.parse_args()
 
 
-def main():
+def main() -> None:
     args = parse_args()
     if args.verbose:
         logging.getLogger().setLevel(logging.DEBUG)

mrtest.py

@@ -3,8 +3,7 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 # PYTHON_ARGCOMPLETE_OK
 
-import sys
 import mrtest.frontend
 
 if __name__ == "__main__":
-    sys.exit(mrtest.frontend.main())
+    mrtest.frontend.main()

mrtest/frontend.py

@@ -69,7 +69,7 @@ def parse_args():
     return parser.parse_args()
 
 
-def main():
+def main() -> None:
     args = parse_args()
     if args.verbose:
         logging.getLogger().setLevel(logging.DEBUG)