reftable: make assignments portable to AIX xlc v12.01
Change the assignment syntax introduced in 66c0dabab5e (reftable: make reftable_record a tagged union, 2022-01-20) to be portable to AIX xlc v12.1: avar@gcc111:[/home/avar]xlc -qversion IBM XL C/C++ for AIX, V12.1 (5765-J02, 5725-C72) Version: 12.01.0000.0000 The error emitted before this was e.g.: "reftable/generic.c", line 133.26: 1506-196 (S) Initialization between types "char*" and "struct reftable_ref_record" is not allowed. The syntax in the pre-image is supported by e.g. xlc 13.01 on a newer AIX version: avar@gcc119:[/home/avar]xlc -qversion IBM XL C/C++ for AIX, V13.1.3 (5725-C72, 5765-J07) Version: 13.01.0003.0006 But as we've otherwise supported this compiler let's not break it entirely if it's easy to work around it. Suggested-by: René Scharfe <l.s.r@web.de> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>