Compiler warnings using MSVC

The following line of code results in an implicit truncation of an uint16_t value to an uint8_t variable, which triggers a compiler warning in MSVC : https://github.com/qemu/qemu/blob/f8c3db33a5e863291182f8862ddf81618a7c6194/hw/usb/dev-hub.c#L387
(Two lines down, the same thing happens.)

This warning can be silenced by doing an explicit truncation, for example by a casting the value explicitly to uint8_t type, or by anding the value with 0xFF.