sock.h: Remove unused NETDEBUG macro

It's unused now, just delete it.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sock.h

@@ -2280,9 +2280,6 @@ bool sk_net_capable(const struct sock *sk, int cap);
  *	Enable debug/info messages
  */
 extern int net_msg_warn;
-#define NETDEBUG(fmt, args...) \
-	do { if (net_msg_warn) printk(fmt,##args); } while (0)
-
 #define LIMIT_NETDEBUG(fmt, args...) \
 	do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)