Declare INCLUDE/EXCLUDE to be local

Intel compiler sets an INCLUDE environmental variable that causes
issues (FS#21233).
Signed-off-by: Allan McRae <allan@archlinux.org>

abs

@@ -101,6 +101,8 @@ version() {
 }
 
 update_rsync() {
+	local INCLUDE EXCLUDE
+
 	cd "$ABSROOT"
 
 	if [ ! "$(type -p rsync)" ]; then