staging: lustre: libcfs: Use list_for_each_entry_safe

Doubly linked lists which are  iterated  using list_empty
and list_entry macros have been replaced with list_for_each_entry_safe
macro.
This makes the iteration simpler and more readable.

This patch replaces the while loop containing list_empty and list_entry
with list_for_each_entry_safe.

This was done with Coccinelle.

@@
expression E1;
identifier I1, I2;
type T;
iterator name list_for_each_entry_safe;
@@

T *I1;
+ T *tmp;
...
- while (list_empty(&E1) == 0)
+ list_for_each_entry_safe (I1, tmp, &E1, I2)
{
...when != T *I1;
- I1 = list_entry(E1.next, T, I2);
...
}

Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lnet/libcfs/workitem.c

@@ -436,6 +436,7 @@ void
 cfs_wi_shutdown(void)
 {
 	struct cfs_wi_sched	*sched;
+	struct cfs_wi_sched *temp;
 
 	spin_lock(&cfs_wi_data.wi_glock);
 	cfs_wi_data.wi_stopping = 1;
@@ -458,9 +459,7 @@ cfs_wi_shutdown(void)
 		}
 		spin_unlock(&cfs_wi_data.wi_glock);
 	}
-	while (!list_empty(&cfs_wi_data.wi_scheds)) {
-		sched = list_entry(cfs_wi_data.wi_scheds.next,
-				   struct cfs_wi_sched, ws_list);
+	list_for_each_entry_safe(sched, temp, &cfs_wi_data.wi_scheds, ws_list) {
 		list_del(&sched->ws_list);
 		LIBCFS_FREE(sched, sizeof(*sched));
 	}