kola: include failed/stuck systemd units in error message directly

Instead of separately logging which systemd units are stuck and failed,
just include it in the fatal error we eventually emit when we print
the test failure. Otherwise it's not easy to match logged messages with
failures when running tests in parallel.

mantle/platform/platform.go

@@ -436,7 +436,7 @@ func checkSystemdUnitStuck(output string, m Machine) error {
 		}
 		NRestarts, _ = strconv.Atoi(string(out))
 		if NRestarts >= 2 {
-			return fmt.Errorf("systemd units %s has %v restarts", unit, NRestarts)
+			return fmt.Errorf("systemd unit %s has %v restarts", unit, NRestarts)
 		}
 	}
 	return nil
@@ -489,7 +489,6 @@ func CheckMachine(ctx context.Context, m Machine) error {
 	// check systemd version on host to see if we can use `busctl --json=short`
 	var systemdVer int
 	var systemdCmd, failedUnitsCmd, activatingUnitsCmd string
-	var systemdFailures bool
 	minSystemdVer := 240
 	out, stderr, err = m.SSH("rpm -q --queryformat='%{VERSION}\n' systemd")
 	if err != nil {
@@ -511,31 +510,23 @@ func CheckMachine(ctx context.Context, m Machine) error {
 	if err != nil {
 		return fmt.Errorf("failed to query systemd for failed units: %s: %v: %s", out, err, stderr)
 	}
-	err = checkSystemdUnitFailures(string(out))
-	if err != nil {
-		plog.Error(err)
-		systemdFailures = true
-	}
+	failed_err := checkSystemdUnitFailures(string(out))
 
 	// Ensure no systemd units stuck in activating state
 	out, stderr, err = m.SSH(activatingUnitsCmd)
 	if err != nil {
 		return fmt.Errorf("failed to query systemd for activating units: %s: %v: %s", out, err, stderr)
 	}
-	err = checkSystemdUnitStuck(string(out), m)
-	if err != nil {
-		plog.Error(err)
-		systemdFailures = true
-	}
+	stuck_err := checkSystemdUnitStuck(string(out), m)
 
-	if systemdFailures && !m.RuntimeConf().AllowFailedUnits {
+	if (failed_err != nil || stuck_err != nil) && !m.RuntimeConf().AllowFailedUnits {
 		if m.RuntimeConf().SSHOnTestFailure {
-			plog.Error("dropping to shell: detected failed or stuck systemd units")
+			plog.Errorf("dropping to shell: detected failed or stuck systemd units: %v; %v", failed_err, stuck_err)
 			if err := Manhole(m); err != nil {
 				plog.Errorf("failed to get terminal via ssh: %v", err)
 			}
 		}
-		return fmt.Errorf("detected failed or stuck systemd units")
+		return fmt.Errorf("detected failed or stuck systemd units: %v; %v", failed_err, stuck_err)
 	}
 
 	return ctx.Err()