LU-3027 clio: Do not shrink sublock at cancel

LU-3027 clio: Do not shrink sublock at cancel

Shrinking sublock at ldlm lock cancel time means whoever happened
to attach to this lock just before will reenqueue the wrong lock.

Test-Parameters: envdefinitions=SLOW=yes,ONLY=write_disjoint \
clientdistro=el6 serverdistro=el6 clientarch=x86_64 \
serverarch=x86_64 testlist=parallel-scale

Change-Id: I8f2de683812621fb2f8d761cf2aceebc12868d75
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Jian Yu <jian.yu@intel.com>
Reviewed-on: http://review.whamcloud.com/7481
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Bobi Jam <bobijam@gmail.com>