MFC r261861
  check for defrag only when bus_dmamap_load_mbuf_sg() returns EFBIG. Comment in
  qla_hw_send is moot.
MFC r259544, r259545, r259546, r259547, r259812, r259939, r260219, r260542,
    r261118, r261124, r261330:

- Add support for the MediaTek/Ralink RT3593 chipset.
- Various minor USB WLAN fixes and improvements.
MFC r257957:

Mention the RT5370/RT5372 chipset.
[automated] Merge in upstream-github/stable/9