xodtemplate: Avoid double-freeing faulty servicegroup members

Previously when we ran into a "members" directive of a servicegroup
where one or more services couldn't be found, we would free() the
input variable to xodtemplate_expand_services(), but without
resetting that variable in the object we were supposed to expand
members for, which caused a double free() when we later tried to
free() memory for the object in question.

This patch corrects that, removing the superfluous free() call.

Reported-by: Mark Frost <mfrost8@gmail.com>
Signed-off-by: Andreas Ericsson <ae@op5.se>
xodtemplate: Free object names last in xodtemplate_free_memory()

When we run into double free()'s and debug the subsequent coredump,
the released memory is sometimes handed back to the kernel before
we can inspect it, or gets overwritten by antihack fortifications.
With this patch, we can be sure to find the names of the object
acting up when we inspect double-free coredumps, which often shortens
the investigation time by quite a large amount.

Signed-off-by: Andreas Ericsson <ae@op5.se>