TAKE - fix fsx test case failure on 1K block fs

[Steve Lord <lord@sgi.com>]

This I think completes the core of the multiple blocksize
support. Still some open issues in O_DIRECT, but this was
a corruption case during random I/O. Filesystems with 
blocksize == pagesize were not affected by this.

Steve

Date:  Mon May 20 13:33:09 PDT 2002
Workarea:  jen.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:119562a
linux/fs/xfs/xfs_vnodeops.c - 1.526
	- remove sethole vop

linux/fs/xfs/linux/xfs_lrw.c - 1.137
	- remove a large chunk of dead code

linux/fs/xfs/linux/xfs_fs_subr.c - 1.29
	- remove fs_pages_sethole - we no longer have a way to call it anyway

linux/fs/xfs/linux/xfs_iops.c - 1.141
	- Pay more attention to buffer_uptodate state.

linux/fs/xfs/linux/xfs_vnode.h - 1.31
	- remove VOP_PAGES_SETHOLE - it is not used

linux/fs/xfs/linux/xfs_fs_subr.h - 1.5
	- remove fs_pages_sethole

linux/fs/xfs/pagebuf/page_buf_io.c - 1.36
	- If a buffer is not uptodate, then we are definitely not supposed to
	  put an extent underneath it.