net: convert BUG_TRAP to generic WARN_ON

Removes legacy reinvent-the-wheel type thing. The generic
machinery integrates much better to automated debugging aids
such as kerneloops.org (and others), and is unambiguous due to
better naming. Non-intuively BUG_TRAP() is actually equal to
WARN_ON() rather than BUG_ON() though some might actually be
promoted to BUG_ON() but I left that to future.

I could make at least one BUILD_BUG_ON conversion.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index 87801cc..16d43f2 100644
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c
@@ -98,7 +98,7 @@
 		    ipv6_addr_equal(&treq->rmt_addr, raddr) &&
 		    ipv6_addr_equal(&treq->loc_addr, laddr) &&
 		    (!treq->iif || treq->iif == iif)) {
-			BUG_TRAP(req->sk == NULL);
+			WARN_ON(req->sk != NULL);
 			*prevp = prev;
 			return req;
 		}