Rook's behavior should not be to create a default OSD in dataDirHostPath
when no devices are present on a node. Any preexisting fallback osd
should be kept as long as no dirs or disks have been specified to keep
the legacy behavior for those clusters running with these osds in place.
The legacy deletion behavior is also kept, removing the osd as soon as
any dir or device is specified other than the dataDirHostPath dir.
Signed-off-by: Blaine Gardner <blaine.gardner@suse.com>