libcxgb: replace vmalloc and memset with vzalloc

Use vzalloc instead of the vmalloc, memset combo
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/libcxgb/libcxgb_ppm.c

@@ -412,12 +412,10 @@ int cxgbi_ppm_init(void **ppm_pp, struct net_device *ndev,
 			ppmax * (sizeof(struct cxgbi_ppod_data)) +
 			ppod_bmap_size * sizeof(unsigned long);
 
-	ppm = vmalloc(alloc_sz);
+	ppm = vzalloc(alloc_sz);
 	if (!ppm)
 		goto release_ppm_pool;
 
-	memset(ppm, 0, alloc_sz);
-
 	ppm->ppod_bmap = (unsigned long *)(&ppm->ppod_data[ppmax]);
 
 	if ((ppod_bmap_size >> 3) > (ppmax - ppmax_pool)) {