PM: Improve error code of pm_notifier_call_chain()

This enables pm_notifier_call_chain() to get the actual error code
in the callback rather than always assume -EINVAL by converting all
PM notifier calls to return encapsulate error code with
notifier_from_errno().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index c47b25f..92d7324 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -814,8 +814,8 @@
 				mutex_unlock(&css->mutex);
 				continue;
 			}
-			if (__chsc_do_secm(css, 0))
-				ret = NOTIFY_BAD;
+			ret = __chsc_do_secm(css, 0);
+			ret = notifier_from_errno(ret);
 			mutex_unlock(&css->mutex);
 		}
 		break;
@@ -831,8 +831,8 @@
 				mutex_unlock(&css->mutex);
 				continue;
 			}
-			if (__chsc_do_secm(css, 1))
-				ret = NOTIFY_BAD;
+			ret = __chsc_do_secm(css, 1);
+			ret = notifier_from_errno(ret);
 			mutex_unlock(&css->mutex);
 		}
 		/* search for subchannels, which appeared during hibernation */