ipconfig: Use time_before

The functions time_before, time_before_eq, time_after, and time_after_eq
are more robust for comparing jiffies against other values.

A simplified version of the Coccinelle semantic patch making this change
is as follows:

@change@
expression E1,E2;
@@
- jiffies - E1 < E2
+ time_before(jiffies, E1+E2)
Signed-off-by: NHimangi Saraogi <himangi774@gmail.com>
Acked-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/ipconfig.c

@@ -262,7 +262,8 @@ static int __init ic_open_devs(void)
 	/* wait for a carrier on at least one device */
 	start = jiffies;
 	next_msg = start + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
-	while (jiffies - start < msecs_to_jiffies(CONF_CARRIER_TIMEOUT)) {
+	while (time_before(jiffies, start +
+			   msecs_to_jiffies(CONF_CARRIER_TIMEOUT))) {
 		int wait, elapsed;
 
 		for_each_netdev(&init_net, dev)