storage_backend_rbd: Drop ATTRIBUTE_UNUSED for arguments that are used
storage_backend_rbd: Drop ATTRIBUTE_UNUSED for arguments that are used

In two places the passed pool object argument is marked as
ATTRIBUTE_UNUSED even though it's used right away.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

eskultety/libvirt,libvirt/libvirt,olafhering/libvirt,zippy2/libvirt,jfehlig/libvirt,crobinso/libvirt,libvirt/libvirt,jardasgit/libvirt,eskultety/libvirt,zippy2/libvirt,andreabolognani/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,libvirt/libvirt,crobinso/libvirt,crobinso/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,eskultety/libvirt,nertpinx/libvirt,crobinso/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,olafhering/libvirt,eskultety/libvirt,eskultety/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,nertpinx/libvirt,nertpinx/libvirt,olafhering/libvirt,olafhering/libvirt,jfehlig/libvirt,zippy2/libvirt,zippy2/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,jardasgit/libvirt,jardasgit/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,libvirt/libvirt