LU-5934 mdt: faulty assertion in mdt_intent_reint

LU-5934 mdt: faulty assertion in mdt_intent_reint

mdt_intent_reint() may set lhc::mlh_reg_lh for resent request,
which means lhc::mlh_reg_lh can be a valid lock handle when
processing of resent request failed and assert(rc == 0) is faulty.

Signed-off-by: Liang Zhen <liang.zhen@intel.com>
Change-Id: I65628d6585cfcec94b820ab631bd391fe77186f2
Reviewed-on: http://review.whamcloud.com/13179
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Li Wei <wei.g.li@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>