Low: Raid1: remove unnecessary wait flags (bsc#1077416)

As per Neil Brown <nfbrown@suse.com>:

In any case it is meaningless to wait for the array to become clean or
for resync to complete after it has already been stopped. Stopping
the array will *always* wait for it to be clean, but will not wait for
resync to complete - it will stop resync gracefully so that it
continues from where it was up to when the array is restarted.