Make sure we don't leak command buffers when a USB command transfer fails.
Make sure we don't leak command buffers when a USB
command transfer fails.

MFC after:	1 week
Reported by:	Ian FREISLICH

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase