[NET]: Dynamically allocate the loopback device, part 1.

This patch replaces all occurences to the static variable
loopback_dev to a pointer loopback_dev. That provides the
mindless, trivial, uninteressting change part for the dynamic
allocation for the loopback.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-By: Kirill Korotaev <dev@sw.ru>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dst.c b/net/core/dst.c
index 38c741a..ad5ffa1 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -278,13 +278,13 @@
 	if (!unregister) {
 		dst->input = dst->output = dst_discard;
 	} else {
-		dst->dev = &loopback_dev;
-		dev_hold(&loopback_dev);
+		dst->dev = loopback_dev;
+		dev_hold(dst->dev);
 		dev_put(dev);
 		if (dst->neighbour && dst->neighbour->dev == dev) {
-			dst->neighbour->dev = &loopback_dev;
+			dst->neighbour->dev = loopback_dev;
 			dev_put(dev);
-			dev_hold(&loopback_dev);
+			dev_hold(dst->neighbour->dev);
 		}
 	}
 }