iscsi: Use error message from virStorageBackendSCSIFindLUs
iscsi: Use error message from virStorageBackendSCSIFindLUs

Don't supercede the error message virStorageBackendSCSIFindLUs as the
message such as "error: Failed to find LUs on host 60: ..." is not overly
clear as to what the real problem might be.

Signed-off-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

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