title: GitLFSPull SCM Jenkins Plugin is not able to do a proper git lfs pull to resolve pointers
body: <p><strong>Background</strong>: I am using Git LFS with the repo, and we need to do a Git LFS pull in the checkout logic while using Jenkins's groovy functions for the Pipeline. What this does is replaces the pointers with the actual files which are later on used during the CI compute phase.</p>
  <p><strong>Problem</strong>: GitLFSPull SCM plugin exists and works without error when used as a scmExtension but it is not giving the expected results, basically the plugin activates, states the below, but I suspect the git lfs pull origin is not working</p>
  <pre><code>Enabling Git LFS pull
   &gt; git rev-parse refs/remotes/origin/feature/xyz^{commit} # timeout=10
   &gt; git rev-parse refs/remotes/origin/origin/feature/xyz^{commit} # timeout=10
   &gt; git config core.sparsecheckout # timeout=10
   &gt; git checkout -f hash # timeout=10
   &gt; git config --get remote.origin.url # timeout=10
   &gt; git lfs pull origin # timeout=10
  
  </code></pre>
  <p>I would like to understand, am I missing something to use the Jenkins plugin correctly ? The below is the Checkout function that we are using</p>
  <pre><code>def checkoutSourceCode(checkoutDir) {
      dir(checkoutDir) {
          checkout changelog: true,
                  poll: true,
                  scm: [$class: 'GitSCM',
                        branches: [[name: &quot;origin/&quot; + params.SOURCE_BRANCH]],
                        doGenerateSubmoduleConfigurations: false,
                        extensions                       : [
                        [$class: 'CloneOption', noTags: true, reference: '', shallow: false],
                        [$class: 'CleanBeforeCheckout'],
                        [$class: 'PruneStaleBranch'],
                        [$class: 'AuthorInChangelog'],
                        [$class: 'GitLFSPull']
                        [$class: 'UserIdentity', email: 'xyz@gmail.com', name: 'xyzzy'],
                        [$class: 'SubmoduleOption',
                                                             disableSubmodules  : false,
                                                             parentCredentials  : true,
                                                             recursiveSubmodules: true,
                                                             reference          : '',
                                                             trackingSubmodules : false]],
                        submoduleCfg                     : [],
                        userRemoteConfigs                : [[name         : 'origin',
                                                             credentialsId: 'xyzzy',
                                                             url          : 'ssh://xyz.xyn.com/something.git']]]
          gitCommit = sh(returnStdout: true, script: 'git rev-parse HEAD').trim()
          shortCommit = gitCommit.take(6)
          return shortCommit
      }
  }
  </code></pre>