crypto: nx - Add of_node_put() before return in 842

Each iteration of for_each_compatible_node puts the previous node, but
in the case of a return from the middle of the loop, there is no put,
thus causing a memory leak. Add an of_node_put before the return.
Issue found with Coccinelle.

Acked-by: Stewart Smith <stewart@linux.ibm.com>
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>