rbd: Set r variable so it can be returned should an error occur
rbd: Set r variable so it can be returned should an error occur

This was reported in bug #1298024 where r would be filled with the
return code of rbd_open().

Should rbd_snap_unprotect() fail for any reason the virReportSystemError
call would return 'Success' since rbd_open() succeeded.

https://bugzilla.redhat.com/show_bug.cgi?id=1298024
Signed-off-by: Wido den Hollander <be4891756a4fdc8c3c6609eb41e49789e971fe07@widodh.nl>

rlaager/libvirt,andreabolognani/libvirt,zippy2/libvirt,taget/libvirt,rlaager/libvirt,rlaager/libvirt,olafhering/libvirt,olafhering/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,datto/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,taget/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,libvirt/libvirt,jardasgit/libvirt,olafhering/libvirt,crobinso/libvirt,eskultety/libvirt,nertpinx/libvirt,datto/libvirt,taget/libvirt,zippy2/libvirt,jardasgit/libvirt,datto/libvirt,zippy2/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,taget/libvirt,zippy2/libvirt,crobinso/libvirt,crobinso/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,jfehlig/libvirt,nertpinx/libvirt,eskultety/libvirt,jardasgit/libvirt,jfehlig/libvirt,eskultety/libvirt,crobinso/libvirt,libvirt/libvirt,rlaager/libvirt,libvirt/libvirt,fabianfreyer/libvirt,libvirt/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,rlaager/libvirt,eskultety/libvirt,VenkatDatta/libvirt,olafhering/libvirt,jfehlig/libvirt,jardasgit/libvirt,datto/libvirt,datto/libvirt,jfehlig/libvirt,eskultety/libvirt,taget/libvirt,andreabolognani/libvirt