powerpc/pseries: Introduce pSeries_reconfig_notify()

This introduces pSeries_reconfig_notify() as a just wrapper of
blocking_notifier_call_chain() for pSeries_reconfig_chain.

This is a preparation to improvement of error code on reconfiguration
notifier failure.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/pseries/dlpar.c

@@ -262,12 +262,11 @@ int dlpar_attach_node(struct device_node *dn)
 	if (!dn->parent)
 		return -ENOMEM;
 
-	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
-					  PSERIES_RECONFIG_ADD, dn);
-	if (rc == NOTIFY_BAD) {
+	rc = pSeries_reconfig_notify(PSERIES_RECONFIG_ADD, dn);
+	if (rc) {
 		printk(KERN_ERR "Failed to add device node %s\n",
 		       dn->full_name);
-		return -ENOMEM; /* For now, safe to assume kmalloc failure */
+		return rc;
 	}
 
 	of_attach_node(dn);
@@ -297,8 +296,7 @@ int dlpar_detach_node(struct device_node *dn)
 		remove_proc_entry(dn->pde->name, parent->pde);
 #endif
 
-	blocking_notifier_call_chain(&pSeries_reconfig_chain,
-			    PSERIES_RECONFIG_REMOVE, dn);
+	pSeries_reconfig_notify(PSERIES_RECONFIG_REMOVE, dn);
 	of_detach_node(dn);
 	of_node_put(dn); /* Must decrement the refcount */