TAKE - some cleanup in log wite path

[Steve Lord <lord@xxxxxxx>]

remove some unused code paths from the log flushing paths, and
remove the callback processing from the log write path, we only
do callbacks on I/O completion now.


Date:  Fri Nov 15 17:31:42 PST 2002
Workarea:  jen.americas.sgi.com:/src/lord/xfs-2.4.20

The following file(s) were checked into:
  bonnie.engr.sgi.com:/isms/slinx/2.4.x-xfs


Modid:  2.4.x-xfs:slinx:133285a
linux/fs/xfs/xfs_log.c - 1.261
        - cleanup and remove xlog_state_do_callback from iclog
          space reservation code.