LU-3110 osd-ldiskfs: Dynamic LBUG in osd declares tracking

This patch implements a dynamic way to enable/disable osd
declaration tracking LBUGs.

OSD_TRACK_DECLARES define usage has been removed, and
tracking of declares is no longer a compile time option.

Enable/disable of declares tracking LBUGs is done via new
global lprocfs "track_declares_assert" boolean, also a
module-parameter.

Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Change-Id: I5164c51c3c3362a77d1a0c7cb7b9f63383b00403
Reviewed-on: http://review.whamcloud.com/6032
Tested-by: Hudson
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>