TAKE - unwritten extent fix

[Steve Lord <lord@xxxxxxx>]

fix a double lock of a buffer head which deadlocked us on 
small blocksize filesystems. Also relocate a balance dirty
call so that we do it a little less often.


Date:  Tue Apr 22 07:46:23 PDT 2003
Workarea:  penguin.americas.sgi.com:/src/lord/xfs-linux.2.4

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


Modid:  2.4.x-xfs:slinx:146520a
linux/fs/xfs/linux/xfs_aops.c - 1.35
        - In the unwritten extent case, remove a call to lock_buffer()
          added in the last mod, this was incorrect and caused
          a deadlock. Also instead of doing balance dirty each
          time we dirty a buffer head, do it once for the whole
          page_state_convert call.