powerpc/icp-hv: Fix missing of_node_put() in success path

Both of_find_compatible_node() and of_find_node_by_type() will return
a refcounted node on success - thus for the success path the node must
be explicitly released with a of_node_put().

Fixes: 0b05ac6e24 ("powerpc/xics: Rewrite XICS driver")
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1530691407-3991-1-git-send-email-hofrat@osadl.org

arch/powerpc/sysdev/xics/icp-hv.c

@@ -174,6 +174,7 @@ int icp_hv_init(void)
 
 	icp_ops = &icp_hv_ops;
 
+	of_node_put(np);
 	return 0;
 }