SCTP: Fix to handle invalid parameter length correctly

If an INIT with invalid parameter length look like this:
Parameter Type : 1
Parameter Length: 800
and not contain any payload, SCTP will ignore this  parameter and send
back a INIT-ACK.
This patch is fix to handle this invalid parameter length correctly.
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>

net/sctp/sm_make_chunk.c

@@ -1833,7 +1833,7 @@ int sctp_verify_init(const struct sctp_association *asoc,
 	 * VIOLATION error.  We build the ERROR chunk here and let the normal
 	 * error handling code build and send the packet.
 	 */
-	if (param.v < (void*)chunk->chunk_end - sizeof(sctp_paramhdr_t)) {
+	if (param.v != (void*)chunk->chunk_end) {
 		sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
 		return 0;
 	}