netns: rename peernet2id() to peernet2id_alloc()

In a following commit, a new function will be introduced to only lookup for
a nsid (no allocation if the nsid doesn't exist). To avoid confusion, the
existing function is renamed.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index f733656..6d1e2ea 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -271,7 +271,7 @@
 #define __net_initconst	__initconst
 #endif
 
-int peernet2id(struct net *net, struct net *peer);
+int peernet2id_alloc(struct net *net, struct net *peer);
 struct net *get_net_ns_by_id(struct net *net, int id);
 
 struct pernet_operations {