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

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>