[NET]: Replace dst_release refcount error with standard WARN_ON

Replace the dst count underflow bug message with a standard WARN message.
This makes errors noticeable and also reduces the kernel text size by 600
since we aren't doing as much to setup the printk.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dst.h

@@ -142,16 +142,11 @@ struct dst_entry * dst_clone(struct dst_entry * dst)
 	return dst;
 }
 
-extern const char dst_underflow_bug_msg[];
-
 static inline
 void dst_release(struct dst_entry * dst)
 {
 	if (dst) {
-		if (atomic_read(&dst->__refcnt) < 1)
-			printk(dst_underflow_bug_msg, 
-			       atomic_read(&dst->__refcnt), 
-			       dst, current_text_addr());
+		WARN_ON(atomic_read(&dst->__refcnt) < 1);
 		atomic_dec(&dst->__refcnt);
 	}
 }

net/core/dst.c

@@ -19,8 +19,6 @@
 
 #include <net/dst.h>
 
-const char dst_underflow_bug_msg[] = KERN_DEBUG "BUG: dst underflow %d: %p at %p\n";
-
 /* Locking strategy:
  * 1) Garbage collection state of dead destination cache
  *    entries is protected by dst_lock.
@@ -275,7 +273,6 @@ void __init dst_init(void)
 	register_netdevice_notifier(&dst_dev_notifier);
 }
 
-EXPORT_SYMBOL(dst_underflow_bug_msg);
 EXPORT_SYMBOL(__dst_free);
 EXPORT_SYMBOL(dst_alloc);
 EXPORT_SYMBOL(dst_destroy);