The return value of get_rbd_dev_path() is only used when $scfg->{krbd}
evaluates to true and the function shouldn't have any side effects
that are needed later, so the call can be avoided otherwise.
This also saves a RADOS connection and command with configurations for
external clusters with krbd disabled.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
e8e477112f