TAKE - fix kdbm_pb builds when page_buf is a module

[Russell Cattelan <n8994@xxxxxxx>]

Modid:  2.3.99pre2-xfs:slinx:61126a
Date:  Tue May  9 13:39:29 PDT 2000
Workarea:  nt8.americas.sgi.com:/data/clink/io/cattelan/x2.3-99-xfs
Author:  cattelan

The following file(s) were checked into:
  bonnie.engr.sgi.com:/isms/slinx/2.3.99pre2-xfs

linux/kdb/modules/kdbm_pb.c - 1.17
http://oss.sgi.com/cgi-bin/cvsweb.cgi/linux-2.4-xfs/linux/kdb/modules/kdbm_pb.c.diff?r1=text&tr1=1.17&r2=text&tr2=1.16&f=h
        - Added defined(CONFIG_PAGE_BUF_MODULE)