LU-4856 misc: Reduce exposure to overflow on page counters.

LU-4856 misc: Reduce exposure to overflow on page counters.

When the number of an object in use or circulation is tied to memory
size of the system, very large memory systems can overflow 32 bit
counters.  This patch addresses overflow on page counters in the osc LRU
and obd accounting.

Signed-off-by: Stephen Champion <schamp@sgi.com>
Change-Id: I8deff55d7cc9774722f3dc38a2c7b15877e698f0
Reviewed-on: http://review.whamcloud.com/10537
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>