powerpc/pseries: use kmemdup rather than duplicating its implementation

The patch was generated using fixed coccinelle semantic patch
scripts/coccinelle/api/memdup.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2014320Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/pseries/hotplug-memory.c

@@ -92,13 +92,12 @@ static struct property *dlpar_clone_drconf_property(struct device_node *dn)
 		return NULL;
 
 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
-	new_prop->value = kmalloc(prop->length, GFP_KERNEL);
+	new_prop->value = kmemdup(prop->value, prop->length, GFP_KERNEL);
 	if (!new_prop->name || !new_prop->value) {
 		dlpar_free_drconf_property(new_prop);
 		return NULL;
 	}
 
-	memcpy(new_prop->value, prop->value, prop->length);
 	new_prop->length = prop->length;
 
 	/* Convert the property to cpu endian-ness */