The signature was still using ATTRIBUTE_UNUSED and actually marked one 
of the used arguments with ATTRIBUTE_UNUSED.

This patch drops the decorations and instead remove the name of 
arguments which are actually unused which is the preferred way to handle 
this now when we can.

Bootstrapped.  I didn't have test results on the platform where I 
bootstrapped, so no results to compare against.  Given its NFC, I think 
we're OK without the regression results.

Pushed to the trunk.
jeff