crypto: crypto4xx - fix a potential double free in ppc4xx_trng_probe

There is a possible double free issue in ppc4xx_trng_probe():

85:	dev->trng_base = of_iomap(trng, 0);
86:	of_node_put(trng);          ---> released here
87:	if (!dev->trng_base)
88:		goto err_out;
...
110:	ierr_out:
111:		of_node_put(trng);  ---> double released here
...

This issue was detected by using the Coccinelle software.
We fix it by removing the unnecessary of_node_put().

Fixes: 5343e674

 ("crypto4xx: integrate ppc4xx-rng into crypto4xx")
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Cc: <stable@vger.kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Allison Randal <allison@lohutok.net>
Cc: Armijn Hemel <armijn@tjaldur.nl>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>