sys/dev/amr build error with Clang

[deeptech71 at gmail.com]

Dimitry Andric wrote:
> The one call to get the callout to amr_periodic() started seems to have
> been commented out in r239912:
>
>    http://svnweb.freebsd.org/base/head/sys/dev/amr/amr.c?r1=239912&r2=239911&pathrev=239912
>
> If the function isn't necessary anymore, it could just be deleted, or
> #ifdef'd out.

I don't use "amr", so I personally don't care whether the use of the function was accidentally commented out or whether the function was accidentally left unused. But on a side-note, to a programmer not familiar with the driver, that case seems like a case of "the use was accidentally commented out".