sound: 6fire: move to use usb_control_msg_send() and usb_control_msg_recv()

The usb_control_msg_send() and usb_control_msg_recv() calls can return
an error if a "short" write/read happens, so move the driver over to
using those calls instead, saving some logic in the wrapper functions
that were being used in this driver.

This also resolves a long-staging bug where data on the stack was being
sent in a USB control message, which was not allowed.

Cc: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200914153756.3412156-8-gregkh@linuxfoundation.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>