gdb: make aarch64_za_offsets_from_regnum return za_offsets

This is not necessary, but it seems more natural to me to make
aarch64_za_offsets_from_regnum return a za_offsets object, rather than
fill an instance passed by parameter.

Change-Id: I40a185f055727da887ce7774be193eef1f4b9147
Approved-by: Luis Machado <luis.machado@arm.com>
Reviewed-By: John Baldwin <jhb@FreeBSD.org>
1 file changed