Intepret EOVERFLOW as babble in Linux USB backend

This adds a missing case to ConvertTransferResult which maps the
low-level error code EOVERFLOW to UsbTransferStatus::BABBLE, indicating
that the device sent more data than was expected.

Bug: 808181
Change-Id: I697171615153e6de53d751f216fc3a2c6287efd5
Reviewed-on: https://chromium-review.googlesource.com/898323Reviewed-by: Matt Reynolds <mattreynolds@chromium.org>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534097}

device/usb/usb_device_handle_usbfs.cc

@@ -111,6 +111,8 @@ UsbTransferStatus ConvertTransferResult(int rc) {
   switch (rc) {
     case 0:
       return UsbTransferStatus::COMPLETED;
+    case EOVERFLOW:
+      return UsbTransferStatus::BABBLE;
     case EPIPE:
       return UsbTransferStatus::STALLED;
     default: