usb_host: Fix incorrect memset() usage in HCD
usb_host: Fix incorrect memset() usage in HCD

This commit fixes incorrect usage of memset() in the HCD's various
_buffer_parse_...() functions. The memset was not clearing the qtd lists, and
were simply setting the first qtd to a non zero value (i.e., the length of
the QTD list).

However, no bug occurred as the subsequent _buffer_fill_...() functions would
overwrite the QTD list anyways.

espressif/esp-idf,espressif/esp-idf,espressif/esp-idf,espressif/esp-idf