Add error message to build description

Change-Id: Ifffce007fbe9d3bc47ea57c30ee652b5e0bdb680
diff --git a/build-debian-packages-libvirt-exporter.groovy b/build-debian-packages-libvirt-exporter.groovy
index eb109cb..aa0c26a 100644
--- a/build-debian-packages-libvirt-exporter.groovy
+++ b/build-debian-packages-libvirt-exporter.groovy
@@ -72,6 +72,7 @@
     } catch (Throwable e) {
        // If there was an exception thrown, the build failed
        currentBuild.result = "FAILURE"
+       currentBuild.description = e.message
        throw e
     } finally {
        common.sendNotification(currentBuild.result,"",["slack"])