[PATCH 10/10] staging: lustre: obdclass: simplify cl_lock_fini()

[NeilBrown]

Using list_first_entry_or_null() makes this (slightly)
simpler.

Signed-off-by: NeilBrown <ne...@suse.com>
---
 drivers/staging/lustre/lustre/obdclass/cl_lock.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/lustre/lustre/obdclass/cl_lock.c 
b/drivers/staging/lustre/lustre/obdclass/cl_lock.c
index 20e64051d2d6..fa97f4b39bd1 100644
--- a/drivers/staging/lustre/lustre/obdclass/cl_lock.c
+++ b/drivers/staging/lustre/lustre/obdclass/cl_lock.c
@@ -78,13 +78,12 @@ EXPORT_SYMBOL(cl_lock_slice_add);
 
 void cl_lock_fini(const struct lu_env *env, struct cl_lock *lock)
 {
+       struct cl_lock_slice *slice;
        cl_lock_trace(D_DLMTRACE, env, "destroy lock", lock);
 
-       while (!list_empty(&lock->cll_layers)) {
-               struct cl_lock_slice *slice;
-
-               slice = list_entry(lock->cll_layers.next,
-                                  struct cl_lock_slice, cls_linkage);
+       while ((slice = list_first_entry_or_null(&lock->cll_layers,
+                                                struct cl_lock_slice,
+                                                cls_linkage)) != NULL) {
                list_del_init(lock->cll_layers.next);
                slice->cls_ops->clo_fini(env, slice);
        }