LU-7626 ldlm: refcount nonzero (1) after lock cleanup

LU-7626 ldlm: refcount nonzero (1) after lock cleanup

It is a regression after LU-2177.
LCK_NL is used by obdecho also.

Perform flock sanity checks only for LDLM_FLOCK.

Change-Id: I83f87b41a13c4d666af36af389ccf1a127197294
Xyratex-bug-id: MRP-2336
Signed-off-by: Andriy Skulysh <andriy.skulysh@seagate.com>
Reviewed-on: http://es-gerrit.xyus.xyratex.com:8080/9406
Tested-by: Jenkins
Reviewed-by: Mirza Arshad Mirza Hussain <arshad.hussain@seagate.com>
Reviewed-by: Alexey Leonidovich Lyashkov <alexey.lyashkov@seagate.com>
Tested-by: Parinay Vijayprakash Kondekar <parinay.kondekar@seagate.com>
Reviewed-on: http://review.whamcloud.com/17791
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>