crypto: crypto4xx - add missing of_node_put after of_device_is_available

Add an of_node_put when a tested device node is not available.

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

// <smpl>
@@
identifier f;
local idexpression e;
expression x;
@@

e = f(...);
... when != of_node_put(e)
    when != x = e
    when != e = x
    when any
if (<+...of_device_is_available(e)...+>) {
  ... when != of_node_put(e)
(
  return e;
|
+ of_node_put(e);
  return ...;
)
}
// </smpl>

Fixes: 5343e674f3 ("crypto4xx: integrate ppc4xx-rng into crypto4xx")
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/amcc/crypto4xx_trng.c

@@ -80,8 +80,10 @@ void ppc4xx_trng_probe(struct crypto4xx_core_device *core_dev)
 
 	/* Find the TRNG device node and map it */
 	trng = of_find_matching_node(NULL, ppc4xx_trng_match);
-	if (!trng || !of_device_is_available(trng))
+	if (!trng || !of_device_is_available(trng)) {
+		of_node_put(trng);
 		return;
+	}
 
 	dev->trng_base = of_iomap(trng, 0);
 	of_node_put(trng);