fsck.h: use designed initializers for FSCK_OPTIONS_{DEFAULT,STRICT}

Refactor the definitions of FSCK_OPTIONS_{DEFAULT,STRICT} to use
designated initializers. This allows us to omit those fields that
are initialized to 0 or NULL.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

fsck.h

@@ -43,8 +43,14 @@ struct fsck_options {
 	kh_oid_map_t *object_names;
 };
 
-#define FSCK_OPTIONS_DEFAULT { NULL, fsck_error_function, 0, NULL, OIDSET_INIT }
-#define FSCK_OPTIONS_STRICT { NULL, fsck_error_function, 1, NULL, OIDSET_INIT }
+#define FSCK_OPTIONS_DEFAULT { \
+	.skiplist = OIDSET_INIT, \
+	.error_func = fsck_error_function \
+}
+#define FSCK_OPTIONS_STRICT { \
+	.strict = 1, \
+	.error_func = fsck_error_function, \
+}
 
 /* descend in all linked child objects
  * the return value is: