md: two small fixes to handling interrupt resync.

1/ If a resync is aborted we should record how far we got
 (recovery_cp) the last request that we know has completed
 (->curr_resync_completed) rather than the last request that was
 submitted (->curr_resync).

2/ When a resync aborts we still want to update the metadata with
 any changes, so set MD_CHANGE_DEVS even if we 'skip'.
Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/md.c

@@ -7333,7 +7333,8 @@ void md_do_sync(struct mddev *mddev)
 					printk(KERN_INFO
 					       "md: checkpointing %s of %s.\n",
 					       desc, mdname(mddev));
-					mddev->recovery_cp = mddev->curr_resync;
+					mddev->recovery_cp =
+						mddev->curr_resync_completed;
 				}
 			} else
 				mddev->recovery_cp = MaxSector;
@@ -7351,9 +7352,9 @@ void md_do_sync(struct mddev *mddev)
 			rcu_read_unlock();
 		}
 	}
+ skip:
 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
 
- skip:
 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
 		/* We completed so min/max setting can be forgotten if used. */
 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))