Log error and return if no devices

tools/dataset/record.cc

@@ -29,6 +29,8 @@ int main(int argc, char *argv[]) {
   glog_init _(argc, argv);
 
   auto &&device = device::select();
+  if (!device)
+    return 1;
   /*
   {  // auto-exposure
     device->SetOptionValue(Option::EXPOSURE_MODE, 0);

tools/writer/device_info_writer.cc

@@ -32,6 +32,8 @@ int main(int argc, char *argv[]) {
   }
 
   auto &&device = device::select();
+  if (!device)
+    return 1;
 
   tools::DeviceWriter writer(device);
   writer.WriteDeviceInfo(filepath);

tools/writer/img_params_writer.cc

@@ -32,6 +32,8 @@ int main(int argc, char *argv[]) {
   }
 
   auto &&device = device::select();
+  if (!device)
+    return 1;
 
   tools::DeviceWriter writer(device);
   writer.WriteImgParams(filepath);

tools/writer/imu_params_writer.cc

@@ -32,6 +32,8 @@ int main(int argc, char *argv[]) {
   }
 
   auto &&device = device::select();
+  if (!device)
+    return 1;
 
   tools::DeviceWriter writer(device);
   writer.WriteImuParams(filepath);

tools/writer/save_all_infos.cc

@@ -29,6 +29,8 @@ int main(int argc, char *argv[]) {
   }
 
   auto &&device = device::select();
+  if (!device)
+    return 1;
 
   dir.append(OS_SEP "SN").append(device->GetInfo()->serial_number);