LU-10963 gnilnd: stats variables overflow assert

Reverse bte rdma transactions stats were being
incremented by kgnilnd_admin_addref() which asserts when the value
goes negative. These stats should be incremented with atomic_inc
instead.

Test-Parameters: trivial
Cray-bug-id: LUS-5940
Signed-off-by: Chuck Fossen <chuckf@cray.com>
Change-Id: I06426bc078cc76f14c7b3efb5f3ceb71054c2d09
Reviewed-on: https://review.whamcloud.com/32184


Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>