NFS: restore module put when manager exits.
Commit
f49169c97fce ("NFSD: Remove svc_serv_ops::svo_module") removed
calls to module_put_and_kthread_exit() from threads that acted as SUNRPC
servers and had a related svc_serv_ops structure. This was correct.
It ALSO removed the module_put_and_kthread_exit() call from
nfs4_run_state_manager() which is NOT a SUNRPC service.
Consequently every time the NFSv4 state manager runs the module count
increments and won't be decremented. So the nfsv4 module cannot be
unloaded.
So restore the module_put_and_kthread_exit() call.
Fixes: f49169c97fce ("NFSD: Remove svc_serv_ops::svo_module")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>