inet{6}_request_sock: Init ->opt and ->pktopts in the constructor

Wei Yongjun noticed that we may call reqsk_free on request sock objects where
the opt fields may not be initialized, fix it by introducing inet_reqsk_alloc
where we initialize ->opt to NULL and set ->pktopts to NULL in
inet6_reqsk_alloc.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 10b666b..cde056e 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -396,8 +396,10 @@
 {
 	struct request_sock *req = reqsk_alloc(ops);
 
-	if (req != NULL)
+	if (req != NULL) {
 		inet_rsk(req)->inet6_rsk_offset = inet6_rsk_offset(req);
+		inet6_rsk(req)->pktopts = NULL;
+	}
 
 	return req;
 }