libmultipath: indicate wwid failure in dm_addmap_create()

libmultipath: indicate wwid failure in dm_addmap_create()

dm_addmap_create() is where we actually try to set up a new
multipath map. Depending on the result, mark the wwid as
failed (or not), and re-trigger an uevent if necessary.
If a path changes from multipath to non-multipath, use an "add"
event to make sure LVM2 rules pick it up. Increase log level
of this event to 3.

Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>