iop-adma: use LIST_HEAD instead of LIST_HEAD_INIT

these three list_head are all local variables, but can also use LIST_HEAD.
Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dma/iop-adma.c

@@ -284,7 +284,7 @@ iop_adma_alloc_slots(struct iop_adma_chan *iop_chan, int num_slots,
 			int slots_per_op)
 {
 	struct iop_adma_desc_slot *iter, *_iter, *alloc_start = NULL;
-	struct list_head chain = LIST_HEAD_INIT(chain);
+	LIST_HEAD(chain);
 	int slots_found, retry = 0;
 
 	/* start search from the last allocated descrtiptor