Clean up y2019 image_streamer a bit

No functional changes.

Change-Id: I843cc6c0a47d93e610abe01c26e0b8ab7c83860e
diff --git a/y2019/image_streamer/image_streamer.cc b/y2019/image_streamer/image_streamer.cc
index cd83a4e..631fcee 100644
--- a/y2019/image_streamer/image_streamer.cc
+++ b/y2019/image_streamer/image_streamer.cc
@@ -110,6 +110,7 @@
 
   void ReadData(void *data, size_t size) {
     PB pb;
+    // TODO(Brian): Do something useful if parsing fails.
     pb.ParseFromArray(data, size);
     proto_callback_(pb);
   }
@@ -141,10 +142,10 @@
   }
 
   void ReadEvent() override {
-    // Ignore reads, but don't leave them pending.
     ssize_t count;
     char buf[512];
     while (true) {
+      // Always read everything so epoll won't return immediately.
       count = read(fd(), &buf, sizeof buf);
       if (count <= 0) {
         if (errno != EAGAIN) {
@@ -320,7 +321,7 @@
   ::std::unique_ptr<CameraStream> camera1;
   ::std::unique_ptr<CameraStream> camera0(new CameraStream(
       params0, "/dev/video0", &tcp_server_, !FLAGS_log.empty(),
-      [&camera0, &camera1, &status_socket, &vision_status]() {
+      [&camera0, &status_socket, &vision_status]() {
         vision_status.set_low_frame_count(vision_status.low_frame_count() + 1);
         LOG(INFO, "Got a frame cam0\n");
         if (camera0->active()) {
@@ -330,7 +331,7 @@
   if (!FLAGS_single_camera) {
     camera1.reset(new CameraStream(
         params1, "/dev/video1", &tcp_server_, false,
-        [&camera0, &camera1, &status_socket, &vision_status]() {
+        [&camera1, &status_socket, &vision_status]() {
           vision_status.set_high_frame_count(vision_status.high_frame_count() +
                                              1);
           LOG(INFO, "Got a frame cam1\n");