LU-4181 lnet_selftest: bogus lst errors

LU-4181 lnet_selftest: bogus lst errors

It should not be counted as errors if a test RPC
has been stopped due to administrative actions,
e.g. lst end_session from the remote test console.

Change-Id: Ia35f5e357ce6bf7ad57efb3652ebb27c772ac611
Signed-off-by: Isaac Huang <he.huang@intel.com>
Reviewed-on: http://review.whamcloud.com/13279
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Amir Shehata <amir.shehata@intel.com>
Reviewed-by: Liang Zhen <liang.zhen@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>