Use valid SSH key for fetching ONOS

Key value was incorrectly specified in the SCM block

Change-Id: I6fc2643c44c18146602f6102c5acdfbdb6da521b
diff --git a/jjb/onos/onos-buck-gerrit-pipeline.yaml b/jjb/onos/onos-buck-gerrit-pipeline.yaml
index 4fe2f5c..e092c71 100644
--- a/jjb/onos/onos-buck-gerrit-pipeline.yaml
+++ b/jjb/onos/onos-buck-gerrit-pipeline.yaml
@@ -31,7 +31,7 @@
             submodule-recursive: false
             choosing-strategy: gerrit
             #jenkins-ssh-credential: '{jenkins-ssh-credential}'
-            jenkins-ssh-credential: 'jenkins'
+            jenkins-ssh-credential: 'onos-jenkins-ssh'
             shallow-clone: true
 
     triggers: