packer: log undefined address/signal as error (commaai#1052)

* LOGE

* no -

can/packer.cc

@@ -42,15 +42,21 @@ CANPacker::CANPacker(const std::string& dbc_name) {
 }
 
 std::vector<uint8_t> CANPacker::pack(uint32_t address, const std::vector<SignalPackValue> &signals) {
-  std::vector<uint8_t> ret(message_lookup[address].size, 0);
+  auto msg_it = message_lookup.find(address);
+  if (msg_it == message_lookup.end()) {
+    LOGE("undefined address %d", address);
+    return {};
+  }
+
+  std::vector<uint8_t> ret(msg_it->second.size, 0);
 
   // set all values for all given signal/value pairs
   bool counter_set = false;
   for (const auto& sigval : signals) {
     auto sig_it = signal_lookup.find(std::make_pair(address, sigval.name));
     if (sig_it == signal_lookup.end()) {
       // TODO: do something more here. invalid flag like CANParser?
-      WARN("undefined signal %s - %d\n", sigval.name.c_str(), address);
+      LOGE("undefined signal %s - %d\n", sigval.name.c_str(), address);
       continue;
     }
     const auto &sig = sig_it->second;