dma-buf: Fix one use-after-free of fence

Need get the new fence when we replace the old one.

Fixes: 047a1b877ed48 ("dma-buf & drm/amdgpu: remove dma_resv workaround")
Signed-off-by: xinhui pan <[e-mail]>
Reviewed-by: Christian König <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]
Signed-off-by: Christian König <[e-mail]>

drivers/dma-buf/dma-resv.c

···
 		if (old->context != context)
 			continue;
 
-		dma_resv_list_set(list, i, replacement, usage);
+		dma_resv_list_set(list, i, dma_fence_get(replacement), usage);
 		dma_fence_put(old);
 	}
 }