staging: lustre: o2iblnd: Use list_for_each_entry_safe in kiblnd_destroy_fmr_pool_list

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.

Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5783
Reviewed-on: http://review.whamcloud.com/17606


Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>