fix(hid): Eliminate data race in USB pathway causing dropped keys

Closes #2253

app/src/usb_hid.c

@@ -18,11 +18,16 @@
 #endif // IS_ENABLED(CONFIG_ZMK_HID_INDICATORS)
 #include <zmk/event_manager.h>
 
+#define HID_EP_WRITE_BUF_SIZE \
+ MAX(MAX(sizeof(zmk_hid_boot_report_t), sizeof(struct zmk_hid_keyboard_report)), \
+ MAX(sizeof(struct zmk_hid_consumer_report), sizeof(struct zmk_hid_mouse_report)))
+
 LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 
 static const struct device *hid_dev;
 
 static K_SEM_DEFINE(hid_sem, 1, 1);
+static uint8_t hid_ep_write_buf[HID_EP_WRITE_BUF_SIZE];
 
 static void in_ready_cb(const struct device *dev) { k_sem_give(&hid_sem); }
 
@@ -137,7 +142,8 @@ static int zmk_usb_hid_send_report(const uint8_t *report, size_t len) {
  return -ENODEV;
  default:
  k_sem_take(&hid_sem, K_MSEC(30));
- int err = hid_int_ep_write(hid_dev, report, len, NULL);
+ memcpy(hid_ep_write_buf, report, len);
+ int err = hid_int_ep_write(hid_dev, hid_ep_write_buf, len, NULL);
 
  if (err) {
  k_sem_give(&hid_sem);