ASoC: rsnd: NULL check is not needed for clk_unprepare()

clk_unprepare() is checking parameter by IS_ERR_OR_NULL().
clk NULL check is not needed on rsnd_mod_quit()
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sh/rcar/core.c

@@ -172,7 +172,6 @@ int rsnd_mod_init(struct rsnd_priv *priv,
 
 void rsnd_mod_quit(struct rsnd_mod *mod)
 {
-	if (mod->clk)
 	clk_unprepare(mod->clk);
 	mod->clk = NULL;
 }