refactor(recurring-job): remove unused method

Signed-off-by: Chin-Ya Huang <chin-ya.huang@suse.com>

app/recurring_job.go

@@ -823,24 +823,6 @@ func (job *Job) GetSettingAsBool(name types.SettingName) (bool, error) {
 	return value, nil
 }
 
-// waitForVolumeState timeout in second
-func (job *Job) waitForVolumeState(state string, timeout int) (*longhornclient.Volume, error) {
-	volumeAPI := job.api.Volume
-	volumeName := job.volumeName
-
-	for i := 0; i < timeout; i++ {
-		volume, err := volumeAPI.ById(volumeName)
-		if err == nil {
-			if volume.State == state {
-				return volume, nil
-			}
-		}
-		time.Sleep(1 * time.Second)
-	}
-
-	return nil, fmt.Errorf("timeout waiting for volume %v to be in state %v", volumeName, state)
-}
-
 // handleAttachmentTicketCreation check and create attachment so that the source volume doesn't get detached during the job.
 func (job *Job) handleAttachmentTicketCreation(volumeName string) (err error) {
 	defer func() {