net: hns3: remove unused head file in hnae3.c

linux/slab.h is not used in hnae3.h, this patch removes it.
Signed-off-by: NPeng Li <lipeng321@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hnae3.c

@@ -8,7 +8,6 @@
  */
 
 #include <linux/list.h>
-#include <linux/slab.h>
 #include <linux/spinlock.h>
 
 #include "hnae3.h"