SCTP: Fix SCTP-AUTH to correctly add HMACS paramter.

There was a typo that cleared the HMACS parameters when no
authenticated chunks were specified.  We whould be clearing
the chunks pointer instead of the hmacs.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

net/sctp/sm_make_chunk.c

@@ -243,7 +243,7 @@ struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
 		if (auth_chunks->length)
 			chunksize += ntohs(auth_chunks->length);
 		else
-			auth_hmacs = NULL;
+			auth_chunks = NULL;
 
 		extensions[num_ext] = SCTP_CID_AUTH;
 		num_ext += 1;