inet: add proper refcounting to request sock

reqsk_put() is the generic function that should be used
to release a refcount (and automatically call reqsk_free())

reqsk_free() might be called if refcount is known to be 0
or undefined.

refcnt is set to one in inet_csk_reqsk_queue_add()

As request socks are not yet in global ehash table,
I added temporary debugging checks in reqsk_put() and reqsk_free()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/request_sock.c b/net/core/request_sock.c
index 04db318..e910317 100644
--- a/net/core/request_sock.c
+++ b/net/core/request_sock.c
@@ -103,7 +103,7 @@
 			while ((req = lopt->syn_table[i]) != NULL) {
 				lopt->syn_table[i] = req->dl_next;
 				lopt->qlen--;
-				reqsk_free(req);
+				reqsk_put(req);
 			}
 		}
 	}
@@ -180,7 +180,7 @@
 		 */
 		spin_unlock_bh(&fastopenq->lock);
 		sock_put(lsk);
-		reqsk_free(req);
+		reqsk_put(req);
 		return;
 	}
 	/* Wait for 60secs before removing a req that has triggered RST.