v5: using nfs4_get_stateowner() instead of an inline function
v3: Update based on Jeff's comments
v2: Fix bad using of struct file_lock_operations for handle the owner
Acked-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: Jeff Layton <jlayton@primarydata.com>