mISDN: use DECLARE_COMPLETION_ONSTACK for non-constant completion

The _ONSTACK variant should be used for on-stack completion,
otherwise it will break lockdep.
 
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Acked-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/mISDN/l1oip_core.c b/drivers/isdn/mISDN/l1oip_core.c
index 7e5f30d..f1e8af5 100644
--- a/drivers/isdn/mISDN/l1oip_core.c
+++ b/drivers/isdn/mISDN/l1oip_core.c
@@ -661,7 +661,7 @@
 	size_t recvbuf_size = 1500;
 	int recvlen;
 	struct socket *socket = NULL;
-	DECLARE_COMPLETION(wait);
+	DECLARE_COMPLETION_ONSTACK(wait);
 
 	/* allocate buffer memory */
 	recvbuf = kmalloc(recvbuf_size, GFP_KERNEL);