drm/nvd0/disp: mask off high 16 bit of negative cursor x-coordinate

commit af5e7d84 upstream.
Signed-off-by: Christoph Bumiller <e0425955@student.tuwien.ac.at>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
[bwh: Backported to 3.2: register value is in the local 'data' variable]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/gpu/drm/nouveau/nvd0_display.c

@@ -472,7 +472,7 @@ static int
 nvd0_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
 {
 	struct nouveau_crtc *nv_crtc = nouveau_crtc(crtc);
-	const u32 data = (y << 16) | x;
+	const u32 data = (y << 16) | (x & 0xffff);
 
 	nv_wr32(crtc->dev, 0x64d084 + (nv_crtc->index * 0x1000), data);
 	nv_wr32(crtc->dev, 0x64d080 + (nv_crtc->index * 0x1000), 0x00000000);