drm/amdgpu: Return earlier in amdgpu_sw_ring_ib_end if mcbp is off

As we don't trigger preemption is sw ring muxer when mcbp is
disabled,so return earlier in amdgpu_sw_ring_ib_end function
if mcbp is disabled ,not required to call amdgpu_ring_mux_end_ib

Signed-off-by: Soham Dandapat <[e-mail]>
Acked-by: Alex Deucher <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu_ring_mux.c

···
 	struct amdgpu_ring_mux *mux = &adev->gfx.muxer;
 
 	WARN_ON(!ring->is_sw_ring);
-	if (ring->hw_prio > AMDGPU_RING_PRIO_DEFAULT)
+	if (adev->gfx.mcbp && ring->hw_prio > AMDGPU_RING_PRIO_DEFAULT)
 		return;
 	amdgpu_ring_mux_end_ib(mux, ring);
 }