Replace JENKINS_URL with JENKINS_PUBLIC_URL

To ensure tf-a-ci-scripts can run on both OpenCI
and Arm Test CI, JENKINS_URL has been replaced with
JENKINS_PUBLIC_URL, as JENKINS_URL is a reserved
private URL in Arm infrastructure.

JENKINS_PUBLIC_URL is a system-wide environment
variable and was configured in:
Manage Jenkins > System > Global Properties

Default values:
OpenCI Production Jenkins: https://ci.trustedfirmware.org/
OpenCI Staging Jenkins: https://ci.staging.trustedfirmware.org/
arm test CI: https://jenkins.openci-test.arm.com/

Change-Id: I3ddf9ebc12f2c9bf045366ee548f23df12656f8f
Signed-off-by: Arthur She <arthur.she@linaro.org>
(cherry picked from commit a813bdf49920a1295f56caa9f79f33334150c911)
diff --git a/script/coverity_wrapper.sh b/script/coverity_wrapper.sh
index 7a0959c..aed88ec 100644
--- a/script/coverity_wrapper.sh
+++ b/script/coverity_wrapper.sh
@@ -35,7 +35,7 @@
 	local need_compare
 
 	# If auth file is not provided and if on Arm infrastructure copy it
-	if [ -z "$auth_file" ] && echo "$JENKINS_URL" | grep -q "oss.arm.com"; then
+	if [ -z "$auth_file" ] && echo "$JENKINS_PUBLIC_URL" | grep -q "oss.arm.com"; then
 		local auth_url="$project_filer/ci-files/coverity/tfcibot@$coverity_host"
 		url="$auth_url" saveas="$workspace/tfcibot@$coverity_host" fetch_file
 		auth_file="$workspace/tfcibot@$coverity_host"