hw/usb: Silence compiler warnings in USB code when compiling with -Wshadow

Rename variables or remove nested definitions where it makes sense,
so that we can finally compile the USB code with "-Wshadow", too.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20231004130822.113343-1-thuth@redhat.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
5 files changed