When the image is not closed, it keeps a watch open. This prevents the
CSI Controller to delete the Volume, as there is still a user of it.
Fixes: f9ab14e826 "rbd: check if an image is part of a group before adding it"
Signed-off-by: Niels de Vos <ndevos@ibm.com>
A RBD image can only be part of a single group. While an image is added
to a group, check if the image is already part of a group, and return an
error in case it is.
Signed-off-by: Niels de Vos <ndevos@ibm.com>
