Merge remote-tracking branch 'remotes/kraxel/tags/vga-20210901-pull-request' into...

vga: misc fixes and cleanups.

# gpg: Signature made Wed 01 Sep 2021 05:18:46 BST
# gpg:                using RSA key A0328CFFB93A17A79901FE7D4CB6D8EED3E87138
# 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/vga-20210901-pull-request:
  hw/display/artist: Fix bug in coordinate extraction in artist_vram_read() and artist_vram_write()
  hw/display/xlnx_dp: fix an out-of-bounds read in xlnx_dp_read
  vga: don't abort when adding a duplicate isa-vga device
  ui/console: Restrict udmabuf_fd() to Linux
  hw/display: Restrict virtio-gpu-udmabuf stubs to !Linux
  virtio-gpu: no point of checking res->iov

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