Make sure that we free the passed in data message if we don't actually insert it onto the queue.  Also, fix a mtx leak if someone turns off devctl while we're processing a messages.
Make sure that we free the passed in data message if we don't actually
insert it onto the queue.  Also, fix a mtx leak if someone turns off
devctl while we're processing a messages.

MFC after:	5 days

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