Refactor main function to clarify intent.

contrib/pg_upgrade/ci/run-test.sh

 #!/usr/bin/env bash
 
-main() {
+create_gpadmin_user() {
 	adduser --disabled-password --gecos "" gpadmin
-	locale-gen en_US.UTF-8
+}
+
+ensure_ssh_daemon_is_running() {
 	service ssh start
+}
+
+setup_utf8_locale() {
+	locale-gen en_US.UTF-8
+}
 
+change_ownership_of_resources_to_gpadmin() {
 	chown -R gpadmin:gpadmin ./gpdb6
 	chown -R gpadmin:gpadmin ./gpdb5
+}
 
+run_test() {
 	su -c ./gpdb6/contrib/pg_upgrade/ci/run-test-as-gpadmin.sh gpadmin
 }
 
+main() {
+	create_gpadmin_user
+	ensure_ssh_daemon_is_running
+	setup_utf8_locale
+	change_ownership_of_resources_to_gpadmin
+	run_test
+}
+
 main "$@"