powerpc/pseries: Fix parent_dn reference leak in add_dt_node()

A reference to the parent device node is held by add_dt_node() for the
node to be added. If the call to dlpar_configure_connector() fails
add_dt_node() returns ENOENT and that reference is not freed.

Add a call to of_node_put(parent_dn) prior to bailing out after a
failed dlpar_configure_connector() call.

Fixes: 8d5ff320 ("powerpc/pseries: Make dlpar_configure_connector parent node aware")
Cc: stable@vger.kernel.org # v3.12+
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/pseries/mobility.c

@@ -226,8 +226,10 @@ static int add_dt_node(__be32 parent_phandle, __be32 drc_index)
 		return -ENOENT;
 
 	dn = dlpar_configure_connector(drc_index, parent_dn);
-	if (!dn)
+	if (!dn) {
+		of_node_put(parent_dn);
 		return -ENOENT;
+	}
 
 	rc = dlpar_attach_node(dn, parent_dn);
 	if (rc)