[NET]: Remove CONFIG_PROC_FS depency for pcounter inuse

The pcounters are initialized for each protocol and could also be used outside
CONFIG_INET context which forces CONFIG_PROC_FS to be set.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>

diff --git a/include/net/sock.h b/include/net/sock.h
index fd98760..505ac6f 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -552,9 +552,7 @@ struct proto {
 	int			(*get_port)(struct sock *sk, unsigned short snum);
 
 	/* Keeping track of sockets in use */
-#ifdef CONFIG_PROC_FS
 	struct pcounter		inuse;
-#endif
 
 	/* Memory pressure */
 	void			(*enter_memory_pressure)(void);