completion: use __gitcomp_builtin in _git_fsck

The new completable options are:

--connectivity-only
--dangling
--progress
--reflogs

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -1499,10 +1499,7 @@ _git_fsck ()
 {
 	case "$cur" in
 	--*)
-		__gitcomp "
+		__gitcomp_builtin fsck "--no-reflogs"
-			--tags --root --unreachable --cache --no-reflogs --full
-			--strict --verbose --lost-found --name-objects
-			"
 		return
 		;;
 	esac