[IPV4] ipconfig: fix RARP ic_servaddr breakage

memcpy 4 bytes to address of auto unsigned long variable followed
by comparison with u32 is a bloody bad idea.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ipconfig.c

@@ -420,7 +420,7 @@ ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt
 {
 	struct arphdr *rarp;
 	unsigned char *rarp_ptr;
-	unsigned long sip, tip;
+	u32 sip, tip;
 	unsigned char *sha, *tha;		/* s for "source", t for "target" */
 	struct ic_device *d;