overseer: send_msg should not return an error (#1995)

* send_message should not return an error

* Apply suggestions from code review

Co-authored-by: Peter Goodspeed-Niklaus <coriolinus@users.noreply.github.com>

* s/send_logging_error/send_and_log_error

Co-authored-by: Peter Goodspeed-Niklaus <coriolinus@users.noreply.github.com>

polkadot/node/overseer/examples/minimal-example.rs

@@ -64,7 +64,7 @@ impl Subsystem1 {
 					}.into(),
 					tx,
 				)
-			)).await.unwrap();
+			)).await;
 		}
 	}
 }