powerprofilesctl: Exit with launched process exit code

This is a regression of commit 18a9c6668, due to the fact that the
argparse func return value is simply ignored.

So let's just exit directly with the provided return value in such case.

src/powerprofilesctl

@@ -139,7 +139,7 @@ def _launch(args):
             ret = launched_app.returncode
     proxy.ReleaseProfile("(u)", cookie)
 
-    return ret
+    sys.exit(ret)
 
 
 def get_parser():

tests/integration_test.py

@@ -1760,6 +1760,18 @@ class Tests(dbusmock.DBusTestCase):
                 tool_cmd + ["--foo-arg", "launch", "true"], stderr=subprocess.PIPE
             )
 
+    def test_launch_with_command_failure(self):
+        self.create_platform_profile()
+        self.start_daemon()
+        self.assert_eventually(lambda: self.get_dbus_property("ActiveProfile"))
+
+        tool_cmd = self.powerprofilesctl_command()
+        cmd = subprocess.run(tool_cmd + ["launch", "false"], check=False)
+        self.assertEqual(cmd.returncode, 1)
+
+        cmd = subprocess.run(tool_cmd + ["launch", "sh", "-c", "exit 55"], check=False)
+        self.assertEqual(cmd.returncode, 55)
+
     def test_vanishing_hold(self):
         self.create_platform_profile()
         self.start_daemon()
@@ -1780,7 +1792,8 @@ class Tests(dbusmock.DBusTestCase):
 
             # Make sure to handle vanishing clients
             launch_process.terminate()
-            self.assertEqual(launch_process.wait(), 0)
+            retcode = launch_process.wait()
+            self.assertTrue(os.WIFSIGNALED(retcode))
 
         holds = self.get_dbus_property("ActiveProfileHolds")
         self.assertEqual(len(holds), 0)