Support BUILD-LATEST symlink

(cherry picked from commit d9a0b019

)
Signed-off-by: Shawn Webb <shawn.webb@hardenedbsd.org>

lib/publish.sh

@@ -26,6 +26,7 @@
 
 publish_release() {
 	mv ${HBSD_STAGEDIR} ${HBSD_PUBDIR}/${HBSD_BUILDNUMBER}
+	ln -sf ${HBSD_BUILDNUMBER} ${HBSD_PUBDIR}/BUILD-LATEST
 	return ${?}
 }