ASoC: rsnd: delete unneeded test before of_node_put

Of_node_put supports NULL as its argument, so the initial test is not
necessary.

Suggested by Uwe Kleine-König.

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression e;
@@

-if (e)
   of_node_put(e);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/sh/rcar/core.c

@@ -798,9 +798,7 @@ if (name##_node) {							\
 			mod_parse(src);
 			mod_parse(dvc);
 
-			if (playback)
 			of_node_put(playback);
-			if (capture)
 			of_node_put(capture);
 		}