nir: Silence unused "options" warning in algebraic passes.

Some passes may not refer to options->..., at which point the compiler
will warn about an unused variable.  Just cast to void unconditionally
to shut it up.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eduardo Lima Mitev <elima@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>

src/compiler/nir/nir_algebraic.py

@@ -291,6 +291,7 @@ ${pass_name}(nir_shader *shader)
    bool progress = false;
    bool condition_flags[${len(condition_list)}];
    const nir_shader_compiler_options *options = shader->options;
+   (void) options;
 
    % for index, condition in enumerate(condition_list):
    condition_flags[${index}] = ${condition};