net: fib_rules: set family in fib_rule_hdr centrally

All fib_rules implementations need to set the family in their ->fill()
functions. Since the value is available to the generic fib_nl_fill_rule()
function, set it there.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/fib_rules.c

@@ -535,6 +535,7 @@ static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
 		return -EMSGSIZE;
 
 	frh = nlmsg_data(nlh);
+	frh->family = ops->family;
 	frh->table = rule->table;
 	NLA_PUT_U32(skb, FRA_TABLE, rule->table);
 	frh->res1 = 0;

net/decnet/dn_rules.c

@@ -196,7 +196,6 @@ static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
 {
 	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
 
-	frh->family = AF_DECnet;
 	frh->dst_len = r->dst_len;
 	frh->src_len = r->src_len;
 	frh->tos = 0;

net/ipv4/fib_rules.c

@@ -213,7 +213,6 @@ static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
 {
 	struct fib4_rule *rule4 = (struct fib4_rule *) rule;
 
-	frh->family = AF_INET;
 	frh->dst_len = rule4->dst_len;
 	frh->src_len = rule4->src_len;
 	frh->tos = rule4->tos;

net/ipv6/fib6_rules.c

@@ -208,7 +208,6 @@ static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
 {
 	struct fib6_rule *rule6 = (struct fib6_rule *) rule;
 
-	frh->family = AF_INET6;
 	frh->dst_len = rule6->dst.plen;
 	frh->src_len = rule6->src.plen;
 	frh->tos = rule6->tclass;