docs/qdev-device-use: Don't suggest -drive and -net can do USB
Commit
480324ec8d "docs/qdev-device-use: Clean up the sentences
related to -usbdevice" deleted the information on syntax that no
longer works. Unfortunately, the resulting text suggests you can
configure USB block devices with -drive, and USB network devices with
-net, which is misleading.
Instead of rephrasing the now misleading text, I'm putting the
information back, and just make clear it's about old versions of QEMU.
Cc: Thomas Huth <thuth@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <
20200806081147.
3123652-4-armbru@redhat.com>