ASoC: codecs: PCM1789: unconditionally flush work

Work is guaranteed to be initialized on exit. Drop the unnecessary
if statement and always call flush_work.

This fixes a warning seen with clang:
sound/soc/codecs/pcm1789.c:265:13: warning: address of 'priv->work' will
always evaluate to 'true' [-Wpointer-bool-conversion]
if (&priv->work)
~~ ~~~~~~^~~~

Signed-off-by: Stefan Agner <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/codecs/pcm1789.c

···
 {
 	struct pcm1789_private *priv = dev_get_drvdata(dev);
 
-	if (&priv->work)
-		flush_work(&priv->work);
+	flush_work(&priv->work);
 
 	return 0;
 }