LU-4577 lnet: Dropped messages are not accounted correctly

LU-4577 lnet: Dropped messages are not accounted correctly

LNET messages that are dropped are not accounted for correctly in
/proc/sys/lnet/stats. What I assume to be a simple typo is causing
drop_length to be double-counted and drop_count to never be
incremented.

Signed-off-by: Matt Ezell <ezellma@ornl.gov>
Change-Id: I761c62b1f3c4c4ceffbe47008b79692a6e643458
Reviewed-on: http://review.whamcloud.com/9096
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Tested-by: Jenkins
Reviewed-by: Isaac Huang <he.huang@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Liang Zhen <liang.zhen@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>