[IFB] After ifb_init_one() failed, i is increased. Decrease

It before entering in the loop for freeing the other ifb devices.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
index 3a42afa..43e3f33 100644
--- a/drivers/net/ifb.c
+++ b/drivers/net/ifb.c
@@ -271,6 +271,7 @@
 	for (i = 0; i < numifbs && !err; i++)
 		err = ifb_init_one(i); 
 	if (err) { 
+		i--;
 		while (--i >= 0)
 			ifb_free_one(i);
 	}