- clear 'rc' if rc == LLOG_EMPTY in llog_init_handle, so we don't free

- clear 'rc' if rc == LLOG_EMPTY in llog_init_handle, so we don't free
  the header and return an error that our caller doesn't expect
- don't call llog_lvfs_pad if left == reclen, only if 0 < left < reclen
- fix the uuid magic in llog_test
- call llog_init_handle in the right places, and don't forget to close
  the log if one of the 1a checks fail