sctp: declare struct sctp_stream before using it

sctp_stream_free uses struct sctp_stream as a param, but struct sctp_stream
is defined after it's declaration.

This patch is to declare struct sctp_stream before sctp_stream_free.

Fixes: a8386317 ("sctp: prepare asoc stream for stream reconf")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/sctp/structs.h

@@ -83,6 +83,7 @@ struct sctp_bind_addr;
 struct sctp_ulpq;
 struct sctp_ep_common;
 struct crypto_shash;
+struct sctp_stream;
 
 
 #include <net/sctp/tsnmap.h>