drm/i915: Discard the request queue if we fail to sleep before suspend

drm/i915: Discard the request queue if we fail to sleep before suspend

If we fail to clear the outstanding request queue before suspending,
mark those requests as lost.

References: https://bugs.freedesktop.org/show_bug.cgi?id=102037
Signed-off-by: Chris Wilson <[email protected]>
Cc: Mika Kuoppala <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Mika Kuoppala <[email protected]>