iavf: Use kzalloc for allocating only one thing

Use kzalloc rather than kcalloc(1,...)

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
@@

- kcalloc(1,
+ kzalloc(
          ...)
// </smpl>
Signed-off-by: NZheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/iavf/iavf_virtchnl.c

@@ -911,7 +911,7 @@ static void iavf_print_link_message(struct iavf_adapter *adapter)
 		return;
 	}
 
-	speed = kcalloc(1, IAVF_MAX_SPEED_STRLEN, GFP_KERNEL);
+	speed = kzalloc(IAVF_MAX_SPEED_STRLEN, GFP_KERNEL);
 	if (!speed)
 		return;