net: ping: fix build failure

If CONFIG_PROC_SYSCTL=n the building process fails:

    ping.c:(.text+0x52af3): undefined reference to `inet_get_ping_group_range_net'

Moved inet_get_ping_group_range_net() to ping.c.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ping.h

@@ -44,8 +44,6 @@ extern struct proto ping_prot;
 extern void ping_rcv(struct sk_buff *);
 extern void ping_err(struct sk_buff *, u32 info);
 
-extern void inet_get_ping_group_range_net(struct net *net, unsigned int *low, unsigned int *high);
-
 #ifdef CONFIG_PROC_FS
 extern int __init ping_proc_init(void);
 extern void ping_proc_exit(void);

net/ipv4/ping.c

@@ -187,6 +187,19 @@ static struct sock *ping_v4_lookup(struct net *net, u32 saddr, u32 daddr,
 	return sk;
 }
 
+static void inet_get_ping_group_range_net(struct net *net, gid_t *low, gid_t *high)
+{
+	gid_t *data = net->ipv4.sysctl_ping_group_range;
+	unsigned seq;
+	do {
+		seq = read_seqbegin(&sysctl_local_ports.lock);
+
+		*low = data[0];
+		*high = data[1];
+	} while (read_seqretry(&sysctl_local_ports.lock, seq));
+}
+
+
 static int ping_init_sock(struct sock *sk)
 {
 	struct net *net = sock_net(sk);

net/ipv4/sysctl_net_ipv4.c

@@ -73,18 +73,6 @@ static int ipv4_local_port_range(ctl_table *table, int write,
 }
 
 
-void inet_get_ping_group_range_net(struct net *net, gid_t *low, gid_t *high)
-{
-	gid_t *data = net->ipv4.sysctl_ping_group_range;
-	unsigned seq;
-	do {
-		seq = read_seqbegin(&sysctl_local_ports.lock);
-
-		*low = data[0];
-		*high = data[1];
-	} while (read_seqretry(&sysctl_local_ports.lock, seq));
-}
-
 void inet_get_ping_group_range_table(struct ctl_table *table, gid_t *low, gid_t *high)
 {
 	gid_t *data = table->data;