dm log: split suspend

There are now two phases to a suspend in device-mapper -
presuspend and postsuspend.  This patch removes the
single 'suspend' in the logging API and replaces it with
'presuspend' and 'postsuspend' functions to align it
better with core device-mapper.

A subsequent patch will make use of 'presuspend'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 2b2ca37..8aafbb7 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -1305,7 +1305,7 @@
 	wait_event(_kmirrord_recovery_stopped,
 		   !atomic_read(&ms->rh.recovery_in_flight));
 
-	if (log->type->suspend && log->type->suspend(log))
+	if (log->type->postsuspend && log->type->postsuspend(log))
 		/* FIXME: need better error handling */
 		DMWARN("log suspend failed");
 }