Detect failure of device information read

If the received data is smaller than the device information size, then
something is wrong.

app/src/device.c

@@ -3,7 +3,8 @@
 
 SDL_bool device_read_info(socket_t device_socket, char *device_name, struct size *size) {
     unsigned char buf[DEVICE_NAME_FIELD_LENGTH + 4];
-    if (net_recv(device_socket, buf, sizeof(buf)) <= 0) {
+    int r = net_recv(device_socket, buf, sizeof(buf));
+    if (r < DEVICE_NAME_FIELD_LENGTH + 4) {
         LOGE("Could not retrieve device information");
         return SDL_FALSE;
     }