usb: host: fotg210: Make use of dma_pool_zalloc() instead of dma_pool_alloc/memset()

Replacing dma_pool_alloc/memset() with dma_pool_zalloc()
to simplify the code.
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20211018131709.487-1-caihuoqing@baidu.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/fotg210-hcd.c

@@ -1859,10 +1859,9 @@ static struct fotg210_qh *fotg210_qh_alloc(struct fotg210_hcd *fotg210,
 	if (!qh)
 		goto done;
 	qh->hw = (struct fotg210_qh_hw *)
-		dma_pool_alloc(fotg210->qh_pool, flags, &dma);
+		dma_pool_zalloc(fotg210->qh_pool, flags, &dma);
 	if (!qh->hw)
 		goto fail;
-	memset(qh->hw, 0, sizeof(*qh->hw));
 	qh->qh_dma = dma;
 	INIT_LIST_HEAD(&qh->qtd_list);