userid-validation: erase score after trigger

The newer versions of Gerrit seem to send events that include the
"Ok-To-Test=1" score on future comments by Jenkins itself.  This can
cause Jenkins to infinite loop itself by seeing its own "Validated=1"
comment _with_ an "Ok-To-Test=1" inside it.  There isn't much capability
to filter this out in the Jenkins Gerrit Trigger Plugin.  Attempt to
work around it by adding immediately erasing the Jenkins Ok-To-Test
score.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I93525b4d8ba7321a5669da4e0296a62cc342fb76
diff --git a/jenkins/userid-validation b/jenkins/userid-validation
index 3a89953..fc882ee 100755
--- a/jenkins/userid-validation
+++ b/jenkins/userid-validation
@@ -95,6 +95,12 @@
         "${GERRIT_CHANGE_NUMBER},${GERRIT_PATCHSET_NUMBER}" \
         --label=Ok-To-Test=1 -t autogenerated:jenkins \
         "--message='User approved, CI ok to start'"
+
+    # Immediately erase the score to prevent infinite triggers.
+    "${GERRIT_SSH_CMD[@]}" review \
+        "${GERRIT_CHANGE_NUMBER},${GERRIT_PATCHSET_NUMBER}" \
+        --label=Ok-To-Test=0 -t autogenerated:jenkins
+
     exit 0
 fi