Don't respond to invalid HTIF operations with assertion failures

They should cause bad behavior in target land rather than crashing the
simulator.

fesvr/device.cc

@@ -41,7 +41,6 @@ void device_t::handle_identify(command_t cmd)
 {
   size_t what = cmd.payload() % command_t::MAX_COMMANDS;
   uint64_t addr = cmd.payload() / command_t::MAX_COMMANDS;
-  assert(addr % IDENTITY_SIZE == 0);
 
   char id[IDENTITY_SIZE] = {0};
   if (what == command_t::MAX_COMMANDS-1)