powerpc/pseries: Failed reconfig notifier chain call cleanup

The return code from invoking the notifier chain when updating the
ibm,dynamic-memory property is not handled properly. In failure
cases (rc == NOTIFY_BAD) we should be restoring the original value
of the property.  In success (rc == NOTIFY_OK) we should be returning
zero from the calling routine.
Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/pseries/reconfig.c

@@ -468,9 +468,13 @@ static int do_update_property(char *buf, size_t bufsize)
 
 		rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
 						  action, value);
+		if (rc == NOTIFY_BAD) {
+			rc = prom_update_property(np, oldprop, newprop);
+			return -ENOMEM;
+		}
 	}
 
-	return rc;
+	return 0;
 }
 
 /**