USB: Fix configuration selection issues introduced in v4.20.0

USB: Fix configuration selection issues introduced in v4.20.0

Commit f13912d3f014a introduced changes to the usb_choose_configuration function
to better support USB Audio UAC3-compatible devices. However, there are a few
problems with this patch. First of all, it adds new "if" clauses in the middle
of an existing "if"/"else if" tree, which obviously breaks pre-existing logic.
Secondly, since it continues iterating over configurations in one of the branches,
other code in the loop can choose an unintended configuration. Finally,
if an audio device's first configuration is UAC3-compatible, and there
are multiple UAC3 configurations, the second one would be chosen, due to
the first configuration never being checked for UAC3-compatibility.

Commit ff2a8c532c14 tries to fix the second issue, but it goes about it in a
somewhat unnecessarily convoluted way, in my opinion, and does nothing
to fix the first or the last one.

This patch tries to rectify problems described by essentially rewriting
code introduced in f13912d3f014a. Notice the code was moved to *before*
the "if"/"else if" tree.

Signed-off-by: Nikolay Yakimov <root@livid.pp.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>