compile cras with gcc 4.9 aarch64

What is the expected output?
compiles

What do you see instead?
cras_alsa_jack.c:596:6: error: variable 'r' set but not used [-Werror=unused-but-set-variable]
  int r;
      ^
cc1: all warnings being treated as errors

This artical:
http://stackoverflow.com/questions/777261/avoiding-unused-variables-warnings-when-using-assert-in-a-release-build

suggest possible work arounds, including:
int Result = Func();
if ( Result == 1 )
{
    assert( 0 );
}