staging: lustre: osc_cache: Use list_for_each_entry_safe

staging: lustre: osc_cache: 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>