staging: android: logger: Change logger_offset() from macro to function

Convert to function and add log as a parameter, rather than relying
on log in the context of the macro.

Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: Ib3c733692b07495d9852b07707ae4dd5ca8b4435