No exception is made for symlinks in the spec, so use

No exception is made for symlinks in the spec, so use
fchmodat(AT_SYMLINK_NOFOLLOW) to set the mode on symlinks, pass
AT_SYMLINK_NOFOLLOW to utimensat(), and then let those be called
on symlinks by dropping the test that skipped them.  Eliminate
set_lids() by changing set_ids() to use fchownat(AT_SYMLINK_NOFOLLOW)
and delete a redundant conditional in each of set_ftime()/fset_ftime().

suggested by espie@
ok millert@