Fix return code ipmiGetSetFirmwareUpdateControl

Update of: ipmiGetSetFirmwareUpdateControl() .
When the command 'update complete' is issued without
FirmwareUpdateControl & TransferStart the error message
"Unspecified error" is returned. An improved respose should be
"Command not supported in present state" with error code 0xd5.
In the log 'transferFirmwareUpdate not started.' is reported.

Tested
==========
Issue command "ipmitool raw 0x08 0x29 0x02" expect return message:
  "Command not supported in present state" with rsp=0xd5

Signed-off-by: Mike Jones <michaelx.jones@intel.com>
Change-Id: I41fd24815d2780016c293ac1e2e38668a6038edc
diff --git a/src/firmware-update.cpp b/src/firmware-update.cpp
index 3f17dac..ea51288 100644
--- a/src/firmware-update.cpp
+++ b/src/firmware-update.cpp
@@ -1359,6 +1359,12 @@
         break;
         case FwUpdateCtrlReq::imageTransferComplete:
         {
+            if (!imageTransferStarted)
+            {
+                phosphor::logging::log<phosphor::logging::level::ERR>(
+                    "transferFirmwareUpdate not started.");
+                return ipmi::responseNotSupportedInPresentState();
+            }
             phosphor::logging::log<phosphor::logging::level::INFO>(
                 "ipmiGetSetFirmwareUpdateControl: Set transfer complete.");
             if (usbAttached)