Some API uses interface number as argument, some wants to have
rhport.
To accommodate need of rhport for functions that don't have it
rhport can be extracted from interface data.
This is helpful if you have already encoded audio data and want an
efficient way to send it. However, this approach is NOT THREADSAFE so
far and works realiably ONLY IF tud_audio_n_write_ep_in_buffer() is NOT
called form an interrupt!
b_bytes_copied was pointer with NULL value instead of
plain variable.
NULL pointer was passed to audio_tx_done_cb() and dereference
as well.
Now variable is not a pointer.
Buffer for TX and RX FIFO was not taking into account
size of element leading to out of bound access.
audio_tx_done_type_I_pcm_ff_cb() reported copied bytes was not returning
correct value number if channels was omitted in computation.
Transfer size calculation uses simpler arithmetic.
In several place p_desc_end calculation was not taking into account
that starting pointer (_audiod_itf[idxDriver].p_desc) was pointing
past interface association descriptor.
It would result in accessing random memory.
