drm/i915: handle failure from vga_get_uninterruptible()

drm/i915: handle failure from vga_get_uninterruptible()

The vga_get_uninterruptible() function can return an error if it fails to
set up VGA decoding for the requested device.

If VGA decoding is unavailable, we don't need to be careful to leave the
VGA emulation in a usable state, as vgacon will also be unable to get
access later on, so just skip over the VGA accesses and the vga_put() call
matching the failed vga_get_uninterruptible().

Signed-off-by: Simon Richter <Simon.Richter@hogyros.de>
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1824
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260306151347.758836-1-Simon.Richter@hogyros.de