drm/nouveau/fbcon/gf100-: reduce RING_SPACE allocation

We only emit 58 words to the ring, not 60.
Signed-off-by: NIlia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvc0_fbcon.c

@@ -188,7 +188,7 @@ nvc0_fbcon_accel_init(struct fb_info *info)
 		return -EINVAL;
 	}
 
-	ret = RING_SPACE(chan, 60);
+	ret = RING_SPACE(chan, 58);
 	if (ret) {
 		WARN_ON(1);
 		nouveau_fbcon_gpu_lockup(info);