Add error message to build description

Change-Id: Ifffce007fbe9d3bc47ea57c30ee652b5e0bdb680
diff --git a/validate-cloud.groovy b/validate-cloud.groovy
index 8381d6e..ec3498a 100644
--- a/validate-cloud.groovy
+++ b/validate-cloud.groovy
@@ -91,6 +91,7 @@
     } catch (Throwable e) {
         // If there was an error or exception thrown, the build failed
         currentBuild.result = "FAILURE"
+        currentBuild.description = e.message
         throw e
     } finally {
         validate.runCleanup(saltMaster, TARGET_NODE, artifacts_dir)