jenkins: move make invocation into shared function

Change-Id: Ied8c1085b8bee2cc4fa65592e805838b8cdae287
diff --git a/contrib/jenkins_common.sh b/contrib/jenkins_common.sh
index a6ffe7f..fa1d544 100644
--- a/contrib/jenkins_common.sh
+++ b/contrib/jenkins_common.sh
@@ -26,3 +26,7 @@
     mkdir -p "$_build_dir"
     cd "$_build_dir"
 }
+
+run_make() {
+    $MAKE $PARALLEL_MAKE check || cat-testlogs.sh
+}