Adjust exit status capture around set options

Co-authored-by: Matías Bellone <toote@users.noreply.github.com>

Author: petetomasik

commands/run.sh

@@ -348,9 +348,8 @@ fi
 
 if [[ "${BUILDKITE_PLUGIN_DOCKER_ALWAYS_PULL:-false}" =~ ^(true|on|1)$ ]] ; then
   echo "--- :docker: Pulling ${image}"
-  retry "${BUILDKITE_PLUGIN_DOCKER_PULL_RETRIES:-3}" docker pull "${image}"
-  retry_exit_status="$?"
-  if [ $retry_exit_status -ne 0 ] ; then
+  retry "${BUILDKITE_PLUGIN_DOCKER_PULL_RETRIES:-3}" docker pull "${image}" || retry_exit_status="$?"
+  if [ ${retry_exit_status:-0} -ne 0 ] ; then
     echo "!!! :docker: Pull failed."
     exit "$retry_exit_status"
   fi