LU-1302 llog: simplify llog_setup functionality

LU-1302 llog: simplify llog_setup functionality

llog catalog used llog_obd_origin_setup as llog_setup() function
It does actually setup, open and llog processing inside that
makes it different from plain llog and breaks new llog API

Patch does the following:

- llog operations are needed for both ctxt and handler, in ctxt
  there are disk and network operations possible, per-handle there
  are plain and catalog llogs. in-handle operations are taken from
  ctxt at first then updated for catalogs by the caller
- rework llog_setup, keep only ctxt allocation in it, remove unused
  parameters, remove llog_setup_named as name was never used

Signed-off-by: Mikhail Pershin <tappro@whamcloud.com>
Change-Id: I8641e697898a1a57bbc500b649f065ba3f2d41b0
Reviewed-on: http://review.whamcloud.com/3949
Tested-by: Hudson
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>