drm/radeon: fix count in cik_sdma_ring_test()

Should be 5 rather than 4.

Noticed-by: Mathias Fröhlich <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>
Cc: [e-mail]
Signed-off-by: Christian König <[e-mail]>

drivers/gpu/drm/radeon/cik_sdma.c

···
 	tmp = 0xCAFEDEAD;
 	writel(tmp, ptr);
 
-	r = radeon_ring_lock(rdev, ring, 4);
+	r = radeon_ring_lock(rdev, ring, 5);
 	if (r) {
 		DRM_ERROR("radeon: dma failed to lock ring %d (%d).\n", ring->idx, r);
 		return r;