Fix last linter issues

internal/commands/classic.go

@@ -8,4 +8,4 @@ type ClassicArgs struct {
 // ClassicOpts holds all flags that are specific to the classic command
 type ClassicOpts struct {
 	AptParams []string `long:"apt-params" description:"Any additional APT specific configuration needed for the image build."` // TODO: is this used?
-}
+}

internal/statemachine/classic_states.go

@@ -1194,6 +1194,7 @@ func (stateMachine *StateMachine) preseedClassicImage() error {
 	// assemble the commands in the correct order: mount, preseed, unmount
 	preseedCmds = append(preseedCmds, mountCmds...)
 	preseedCmds = append(preseedCmds,
+		//nolint:gosec,G204
 		exec.Command("/usr/lib/snapd/snap-preseed", stateMachine.tempDirs.chroot),
 	)
 	preseedCmds = append(preseedCmds, umountCmds...)

internal/statemachine/helper.go

@@ -1079,7 +1079,15 @@ func (stateMachine *StateMachine) updateGrub(rootfsVolName string, rootfsPartNum
 		"--detach",
 		loopUsed,
 	)
-	defer teardownCmd.Run()
+	defer func() {
+		if tmpErr := teardownCmd.Run(); tmpErr != nil {
+			if err != nil {
+				err = fmt.Errorf("%s after previous error: %w", tmpErr, err)
+			} else {
+				err = tmpErr
+			}
+		}
+	}()
 	updateGrubCmds = append(updateGrubCmds, teardownCmd)
 
 	// now run all the commands