nouveau: fix fence waiting logic in screen destroy

nouveau_fence_wait has the expectation that an external entity is
holding onto the fence being waited on, not that it is merely held onto
by the current pointer. Fixes a use-after-free in nouveau_fence_wait
when used on the screen's current fence.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75279
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: "9.2 10.0 10.1" <mesa-stable@lists.freedesktop.org>
nv50,nvc0: adjust blit_3d handling of ms output textures

This fixes some unwanted scaling when the output is multisampled. Also
increases nvc0 maximum supported texture size to be able to work with a
32k texture.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: "10.0 10.1" <mesa-stable@lists.freedesktop.org>