dmaengine: ppc4xx: Make use of the helper macro LIST_HEAD()

Replace "struct list_head head = LIST_HEAD_INIT(head)" with
"LIST_HEAD(head)" to simplify the code.

Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev>
Link: https://lore.kernel.org/r/20220209032221.37211-1-cai.huoqing@linux.dev
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: caihuoq

drivers/dma/ppc4xx/adma.c

@@ -1686,8 +1686,8 @@ static struct ppc440spe_adma_desc_slot *ppc440spe_adma_alloc_slots(
 {
 	struct ppc440spe_adma_desc_slot *iter = NULL, *_iter;
 	struct ppc440spe_adma_desc_slot *alloc_start = NULL;
-	struct list_head chain = LIST_HEAD_INIT(chain);
 	int slots_found, retry = 0;
+	LIST_HEAD(chain);
 
 
 	BUG_ON(!num_slots || !slots_per_op);