Fix coverage on remote xdist nodes

scripts/Jenkinsfiles/python

@@ -27,6 +27,14 @@ def pythonTestCleanup() {
     bash scripts/xdist/terminate_xdist_nodes.sh'''
 }
 
+def xdist_git_branch() {
+    if (env.ghprbActualCommit) {
+        return "${ghprbActualCommit}"
+    } else {
+        return "${BRANCH_NAME}"
+    }
+}
+
 pipeline {
     agent { label "jenkins-worker" }
     options {
@@ -37,7 +45,7 @@ pipeline {
         XDIST_CONTAINER_SUBNET = credentials('XDIST_CONTAINER_SUBNET')
         XDIST_CONTAINER_SECURITY_GROUP = credentials('XDIST_CONTAINER_SECURITY_GROUP')
         XDIST_CONTAINER_TASK_NAME = "jenkins-worker-task"
-        XDIST_GIT_BRANCH = "${ghprbActualCommit}"
+        XDIST_GIT_BRANCH = xdist_git_branch()
     }
     stages {
         stage('Mark build as pending on Github') {

scripts/xdist/prepare_xdist_nodes.sh

@@ -13,7 +13,7 @@ do
     container_reqs_cmd="ssh -o StrictHostKeyChecking=no ubuntu@$ip 'cd /edx/app/edxapp;
     git clone --branch master --depth 1 --no-tags -q https://github.com/edx/edx-platform.git; cd edx-platform;
     git fetch --depth=1 --no-tags -q origin ${XDIST_GIT_BRANCH}; git checkout -q ${XDIST_GIT_BRANCH};
-    source /edx/app/edxapp/edxapp_env; pip install -qr requirements/edx/testing.txt' & "
+    source /edx/app/edxapp/edxapp_env; pip install -qr requirements/edx/testing.txt; mkdir reports' & "
 
     cmd=$cmd$container_reqs_cmd
 done