LOCKD: Clear ln->nsm_clnt only when ln->nsm_users is zero
LOCKD: Clear ln->nsm_clnt only when ln->nsm_users is zero

The current code is clearing it in all cases _except_ when zero.

Reported-by: Stanislav Kinsbursky <43b28e187c4fe6e53d7ab0bb71957481e322f182@parallels.com>
Signed-off-by: Trond Myklebust <6a1f9db795c9fc44be97d66ab114c53193bd3d13@netapp.com>
Cc: 4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs