dmaengine: stm32-dmamux: Fix PM disable depth imbalance in stm32_dmamux_probe

The pm_runtime_enable will increase power disable depth.
If the probe fails, we should use pm_runtime_disable() to balance
pm_runtime_enable().

Fixes: 4f3ceca ("dmaengine: stm32-dmamux: Add PM Runtime support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20220108085336.11992-1-linmq006@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: Yuuoniy

drivers/dma/stm32-dmamux.c

@@ -292,10 +292,12 @@ static int stm32_dmamux_probe(struct platform_device *pdev)
 	ret = of_dma_router_register(node, stm32_dmamux_route_allocate,
 				     &stm32_dmamux->dmarouter);
 	if (ret)
-		goto err_clk;
+		goto pm_disable;
 
 	return 0;
 
+pm_disable:
+	pm_runtime_disable(&pdev->dev);
 err_clk:
 	clk_disable_unprepare(stm32_dmamux->clk);