udev skips every key of a rule whose IMPORT{program} fails, OWNER and GROUP
included, and vitastor-disk udev exits 1 when it rejects the superblock. A
freshly added partition whose check failed stayed root:disk, and an OSD
opening it as user vitastor got EACCES. This happens with dm-multipath: the
dm partition's ready event is checked while by-partuuid still points at the
path partition. Assign ownership by partition type alone; the alias symlink
still needs a valid superblock.
