Ticket 48284 - free entry when internal add fails
    
    Bug Description:  The entry passed to an internal add operaton is expected
                      to be consumed, but it is not freed during an internal
                      add when setting slapi_add_internal_pb() returns an error.
    
    Fix Description:  Free the entry in slapi_add_internal_pb() when the operation
                      is not allowed.
    
    https://fedorahosted.org/389/ticket/48284
    
    Reviewed by: nhosoi(Thanks!)
    
    (cherry picked from commit 622be8bfbc942fe100b8880df72db26e99e1c954)
    (cherry picked from commit 82b4347bf7f8b29bd5e3e7734daa4aaa465fa57c)