staging: lustre: 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>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4856
Reviewed-on: http://review.whamcloud.com/10537


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>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>