Extra Bytes in response data for chassis Identify command

From IPMI spec, response should be complete code only.

Tested:
ipmitool raw 0x00 0x04 0x02 0x00

Change-Id: I48a9f71e01c89ee1125d515c50e3e2655510d0ce
Signed-off-by: Jia, Chunhui <chunhui.jia@linux.intel.com>
diff --git a/chassishandler.cpp b/chassishandler.cpp
index c9885bd..c955658 100644
--- a/chassishandler.cpp
+++ b/chassishandler.cpp
@@ -1223,6 +1223,7 @@
             ? (static_cast<uint8_t*>(request))[forceIdentifyPos] & 0x01
             : false;
 
+    *data_len = 0; // response have complete code only
     if (identifyInterval || forceIdentify)
     {
         // stop the timer if already started, for force identify we should