usb: musb: am35x: use platform_device_unregister in am35x_remove()

platform_device_unregister() only calls platform_device_del() and
platform_device_put(), thus use platform_device_unregister() to
simplify the code.

Also the documents in platform.c shows that platform_device_del
and platform_device_put must _only_ be externally called in error
cases.  All other usage is a bug.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/musb/am35x.c

@@ -572,8 +572,7 @@ static int __devexit am35x_remove(struct platform_device *pdev)
 	struct am35x_glue	*glue = platform_get_drvdata(pdev);
 
 	musb_put_id(&pdev->dev, glue->musb->id);
-	platform_device_del(glue->musb);
-	platform_device_put(glue->musb);
+	platform_device_unregister(glue->musb);
 	clk_disable(glue->clk);
 	clk_disable(glue->phy_clk);
 	clk_put(glue->clk);