[NET]: Marking struct pernet_operations __net_initdata was inappropriate

It is not safe to to place struct pernet_operations in a special section.
We need struct pernet_operations to last until we call unregister_pernet_subsys.
Which doesn't happen until module unload.

So marking struct pernet_operations is a disaster for modules in two ways.
- We discard it before we call the exit method it points to.
- Because I keep struct pernet_operations on a linked list discarding
  it for compiled in code removes elements in the middle of a linked
  list and does horrible things for linked insert.

So this looks safe assuming __exit_refok is not discarded
for modules.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/net_namespace.h

@@ -102,11 +102,9 @@ static inline void release_net(struct net *net)
 #ifdef CONFIG_NET_NS
 #define __net_init
 #define __net_exit
-#define __net_initdata
 #else
 #define __net_init	__init
 #define __net_exit	__exit_refok
-#define __net_initdata	__initdata
 #endif
 
 struct pernet_operations {