webadmin: All LUNs appeared incorrecly under each target

Fixed a bug in which all LUNs in the host were appearing under each and
every target incorrectly

Change-Id: I9872cf89c49e64101005480d0c6363427e7072f2
Bug-Url: https://bugzilla.redhat.com/951928
Signed-off-by: Tal Nisan <tnisan@redhat.com>