libblkid: iso9660: use sizeof_member

diff --git a/libblkid/src/superblocks/iso9660.c b/libblkid/src/superblocks/iso9660.c
index e67da9d70673508455d31571a4e0595a1557a888..49e0530edf14cf0970541352baac709ea4a8be73 100644 (file)
--- a/libblkid/src/superblocks/iso9660.c
+++ b/libblkid/src/superblocks/iso9660.c
@@ -74,7 +74,7 @@ struct boot_record {
 #define ISO_VD_END                     0xff
 #define ISO_VD_MAX                     16
 /* maximal string field size used anywhere in ISO; update if necessary */
-#define ISO_MAX_FIELDSIZ  sizeof(((struct iso_volume_descriptor  *)0)->volume_set_id)
+#define ISO_MAX_FIELDSIZ  sizeof_member(struct iso_volume_descriptor, volume_set_id)
 
 struct high_sierra_volume_descriptor {
        unsigned char   foo[8];