dmaengine: xgene-dma: use dma_pool_zalloc

We should use shiny new dma_pool_zalloc instead of
dma_pool_alloc/memset
Reported-by: NJulia Lawall <julia.lawall@lip6.fr>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

drivers/dma/xgene-dma.c

@@ -556,14 +556,12 @@ static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
 	struct xgene_dma_desc_sw *desc;
 	dma_addr_t phys;
 
-	desc = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT, &phys);
+	desc = dma_pool_zalloc(chan->desc_pool, GFP_NOWAIT, &phys);
 	if (!desc) {
 		chan_err(chan, "Failed to allocate LDs\n");
 		return NULL;
 	}
 
-	memset(desc, 0, sizeof(*desc));
-
 	INIT_LIST_HEAD(&desc->tx_list);
 	desc->tx.phys = phys;
 	desc->tx.tx_submit = xgene_dma_tx_submit;