drm/virtio: Fix type of dma-fence context variable

Type of DMA fence context is u64. Fence-waiting code uses u32 for the
context variable, fix it.

Fixes: e4812ab8e6b1 ("drm/virtio: Refactor and optimize job submission code path")
Cc: <[e-mail]> # v6.4+
Signed-off-by: Dmitry Osipenko <[e-mail]>
Reviewed-by: Rob Clark <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/virtio/virtgpu_submit.c

···
 static int virtio_gpu_do_fence_wait(struct virtio_gpu_submit *submit,
 				    struct dma_fence *in_fence)
 {
-	u32 context = submit->fence_ctx + submit->ring_idx;
+	u64 context = submit->fence_ctx + submit->ring_idx;
 
 	if (dma_fence_match_context(in_fence, context))
 		return 0;