TAKE - minor pagebuf code cleanup

[lord@xxxxxxx]

Date:  Mon Jul 24 14:32:09 PDT 2000
Workarea:  pinky.cray.com:/usr/src/lord/2.4.0-test1

The following file(s) were checked into:
  bonnie.engr.sgi.com:/isms/slinx/2.4.0-test1-xfs


Modid:  2.4.0-test1-xfs:slinx:67692a
linux/include/linux/page_buf.h - 1.54
        - Remove unused macros, correct some others to use PAGE_CACHE_xxx 
macros,
          remove prototypes for functions no longer in the source

linux/kdb/modules/kdbm_pg.c - 1.6
        - Remove references to the count_residual field in the pagebuf

linux/fs/pagebuf/page_buf.c - 1.15
        - Remove some unused code including the count_residual field in the
          pagebuf.