staging: lustre: osc: 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/lustre/osc/osc_page.c

@@ -563,6 +563,7 @@ int osc_lru_shrink(struct client_obd *cli, int target)
 	struct cl_object *clobj = NULL;
 	struct cl_page **pvec;
 	struct osc_page *opg;
+	struct osc_page *temp;
 	int maxscan = 0;
 	int count = 0;
 	int index = 0;
@@ -582,14 +583,12 @@ int osc_lru_shrink(struct client_obd *cli, int target)
 	client_obd_list_lock(&cli->cl_lru_list_lock);
 	atomic_inc(&cli->cl_lru_shrinkers);
 	maxscan = min(target << 1, atomic_read(&cli->cl_lru_in_list));
-	while (!list_empty(&cli->cl_lru_list)) {
+	list_for_each_entry_safe(opg, temp, &cli->cl_lru_list, ops_lru) {
 		struct cl_page *page;
 
 		if (--maxscan < 0)
 			break;
 
-		opg = list_entry(cli->cl_lru_list.next, struct osc_page,
-				 ops_lru);
 		page = cl_page_top(opg->ops_cl.cpl_page);
 		if (cl_page_in_use_noref(page)) {
 			list_move_tail(&opg->ops_lru, &cli->cl_lru_list);