dbus: fix CVE-2022-42012 dbus-marshal-byteswap: Byte-swap Unix fd indexes if needed

Backport a patch from upstream [1] to fix CVE-2022-42012
dbus-marshal-byteswap: Byte-swap Unix fd indexes if needed

[1] https://gitlab.freedesktop.org/dbus/dbus/-/commit/3fb065b0752db1e298e4ada52cf4adc414f5e946



Signed-off-by: Xiangyu Chen <xiangyu.chen@eng.windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>