cls_bpf: Use kmemdup instead of duplicating it in cls_bpf_prog_from_ops

Replace calls to kmalloc followed by a memcpy with a direct call to
kmemdup.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sched/cls_bpf.c

@@ -349,12 +349,10 @@ static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
 	if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
 		return -EINVAL;
 
-	bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
+	bpf_ops = kmemdup(nla_data(tb[TCA_BPF_OPS]), bpf_size, GFP_KERNEL);
 	if (bpf_ops == NULL)
 		return -ENOMEM;
 
-	memcpy(bpf_ops, nla_data(tb[TCA_BPF_OPS]), bpf_size);
-
 	fprog_tmp.len = bpf_num_ops;
 	fprog_tmp.filter = bpf_ops;