CI: improve log artifacts

Putting the Kubernetes version nearer the start of the file names ensures that
files for the same test case are grouped together when sorting. Sorting by the
type of content is less useful because usually one wants to investigate a
specific test failure which occurred under a specific Kubernetes version.

Splitting up log messages by node makes the individual files smaller and
simplifies debugging of a problem that occurred on a specific node.

To debug the spontanuous node
reboot (intel#1055) the full systemd journal
is needed.

Jenkinsfile

@@ -515,9 +515,9 @@ void TestInVM(worker, distro, distroVersion, kubernetesVersion, skipIfPR) {
            "
     } } finally {
         echo "Writing cluster state and kubelet logs into files."
-        sh "_work/${env.CLUSTER}/ssh.0 kubectl get nodes -o wide > joblog-${BUILD_TAG}-nodestate-${kubernetesVersion}.log"
-        sh "_work/${env.CLUSTER}/ssh.0 kubectl get pods --all-namespaces -o wide > joblog-${BUILD_TAG}-podstate-${kubernetesVersion}.log"
-        sh "for cmd in `ls _work/${env.CLUSTER}/ssh.*`; do \$cmd sudo journalctl -u kubelet >> joblog-${BUILD_TAG}-kubeletlogs-${kubernetesVersion}.log; done"
+        sh "_work/${env.CLUSTER}/ssh.0 kubectl get nodes -o wide > joblog-${BUILD_TAG}-${kubernetesVersion}-nodestate.log"
+        sh "_work/${env.CLUSTER}/ssh.0 kubectl get pods --all-namespaces -o wide > joblog-${BUILD_TAG}-${kubernetesVersion}-podstate.log"
+        sh "for cmd in `ls _work/${env.CLUSTER}/ssh.*`; do suffix=`basename \$cmd | sed -e s/^ssh.//`; \$cmd sudo journalctl -u kubelet > joblog-${BUILD_TAG}-${kubernetesVersion}-kubelet.\${suffix}.log; \$cmd sudo journalctl > joblog-${BUILD_TAG}-${kubernetesVersion}-journal-\${suffix}.log; done"
         // Each test run produces junit_*.xml files with testsuite name="PMEM E2E suite".
         // To make test names unique in the Jenkins UI, we rename that test suite per run,
         // mangle the <testcase name="..." classname="..."> such that