Merge remote-tracking branch 'remotes/kraxel/tags/fixes-20200713-pull-request' into staging

bugfixes for audio, usb, ui and docs.

# gpg: Signature made Mon 13 Jul 2020 15:10:35 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/fixes-20200713-pull-request:
  usb: fix usb-host build on windows.
  ui: fix vc_chr_write call in text_console_do_init
  docs/qdev-device-use: Clean up the sentences related to -usbdevice
  ossaudio: fix out of bounds write

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>