Improved setting error messages to jenkins job descriptions

Change-Id: Ia19224b7334d6fd468ecc40be87d5b4df795adc5
diff --git a/openstack-compute-upgrade.groovy b/openstack-compute-upgrade.groovy
index 658d5be..095697d 100644
--- a/openstack-compute-upgrade.groovy
+++ b/openstack-compute-upgrade.groovy
@@ -199,7 +199,7 @@
     } catch (Throwable e) {
         // If there was an error or exception thrown, the build failed
         currentBuild.result = "FAILURE"
-        currentBuild.description = e.message
+        currentBuild.description = currentBuild.description ? e.message + " " + currentBuild.description : e.message
         throw e
     }
 }