libctf: fix GNU style for do {} while

libctf: fix GNU style for do {} while

It's formatted like this:

do
  {
    ...
  }
while (...);

Not like this:

do
 {
    ...
  } while (...);

or this:

do {
  ...
} while (...);

We used both in various places in libctf.  Fixing it necessitated some
light reindentation.

libctf/ChangeLog
2021-03-18  Nick Alcock  <nick.alcock@oracle.com>

	* ctf-archive.c (ctf_archive_next): GNU style fix for do {} while.
	* ctf-dedup.c (ctf_dedup_rhash_type): Likewise.
	(ctf_dedup_rwalk_one_output_mapping): Likewise.
	* ctf-dump.c (ctf_dump_format_type): Likewise.
	* ctf-lookup.c (ctf_symbol_next): Likewise.
	* swap.h (swap_thing): Likewise.