devfreq/exynos-bus: Use common error handling code in exynos_bus_target()

From: SF Markus Elfring <hidden>
Date: 2017-10-23 05:53:45
Also in: kernel-janitors, linux-pm, linux-samsung-soc, lkml

As I already commented on your other patch related to extcon-max14577,
this patch might remove the redundant error message.

I hope that more software improvements can be achieved in this design direction.

But, it makes the code more complicated in side of readability. I prefer existing code.

I prefer to avoid duplicated code a bit more.

Regards,
Markus