net: ipv4: Remove unneed BUG() function

When 'nla_parse_nested_deprecated' failed, it's no need to
BUG() here, return -EINVAL is ok.
Signed-off-by: NZheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/devinet.c

@@ -1989,7 +1989,7 @@ static int inet_set_link_af(struct net_device *dev, const struct nlattr *nla,
 		return -EAFNOSUPPORT;
 
 	if (nla_parse_nested_deprecated(tb, IFLA_INET_MAX, nla, NULL, NULL) < 0)
-		BUG();
+		return -EINVAL;
 
 	if (tb[IFLA_INET_CONF]) {
 		nla_for_each_nested(a, tb[IFLA_INET_CONF], rem)

net/ipv6/addrconf.c

@@ -5827,7 +5827,7 @@ static int inet6_set_link_af(struct net_device *dev, const struct nlattr *nla,
 		return -EAFNOSUPPORT;
 
 	if (nla_parse_nested_deprecated(tb, IFLA_INET6_MAX, nla, NULL, NULL) < 0)
-		BUG();
+		return -EINVAL;
 
 	if (tb[IFLA_INET6_TOKEN]) {
 		err = inet6_set_iftoken(idev, nla_data(tb[IFLA_INET6_TOKEN]),