LU-3707 target: fix trans call back for out

LU-3707 target: fix trans call back for out

Since OUT and MDT share the same trans callback
route path, move mti_has_trans from mdt_thread_info to
tgt_session_info, so avoid confusing out transaction.

Test-Parameters: mdtcount=2 mdscount=2
Signed-off-by: wang di <di.wang@intel.com>
Change-Id: I8eee17645487a3a3eced6862743bc35b83fc2c24
Reviewed-on: http://review.whamcloud.com/7256
Tested-by: Hudson
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>