innobase/include/log0log.h:
  Remove debug variables unless #ifdef UNIV_LOG_DEBUG
innobase/include/log0log.ic:
  Remove log_check_log_recs() unless #ifdef UNIV_LOG_DEBUG
innobase/log/log0log.c:
  Remove log_debug_writes unless #ifdef UNIV_LOG_DEBUG
  log_io_complete_checkpoint(): Remove parameter; move debug output to log_io_complete(), the only caller
  Test log_debug_writes only #ifdef UNIV_LOG_DEBUG
innobase/log/log0recv.c:
  Test log_debug_writes only #ifdef UNIV_LOG_DEBUG