PM / Suspend: Avoid code duplication in suspend statistics update

The code
       if (error) {
               suspend_stats.fail++;
               dpm_save_failed_errno(error);
       } else
               suspend_stats.success++;

Appears in the kernel/power/main.c and kernel/power/suspend.c.

This patch just creates a new function to avoid duplicated code.

Suggested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Marcos Paulo de Souza <marcos.mage@gmail.com>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 560a639..03bc92b 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -321,11 +321,7 @@
 	int ret;
 	if (state > PM_SUSPEND_ON && state < PM_SUSPEND_MAX) {
 		ret = enter_state(state);
-		if (ret) {
-			suspend_stats.fail++;
-			dpm_save_failed_errno(ret);
-		} else
-			suspend_stats.success++;
+		suspend_stats_update(ret);
 		return ret;
 	}
 	return -EINVAL;