TAKE - io path cleanups

[Steve Lord <lord@sgi.com>]

Nothing major here, just cleanup

Date:  Mon Jul  8 15:09:30 PDT 2002
Workarea:  jen.americas.sgi.com:/src/lord/xfs-vanilla

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


Modid:  2.4.x-xfs:slinx:122666a
linux/fs/xfs/xfs_rw.h - 1.65
linux/fs/xfs/xfs_rw.c - 1.358
linux/fs/xfs/xfs_vnodeops.c - 1.534
linux/fs/xfs/xfs_dfrag.c - 1.31
	- changes xfs_inval_cached_pages interface

linux/fs/xfs/linux/xfs_lrw.c - 1.151
	- move pagebuf_iozero here, relocate xfs stats here, change 
	  xfs_inval_cached_pages interface

linux/fs/xfs/linux/xfs_file.c - 1.68
	- move xfs stats into xfs

linux/fs/xfs/pagebuf/page_buf_io.c - 1.47
linux/fs/xfs/pagebuf/page_buf.h - 1.22
	- remove pagebuf_iozero from here