Ticket 49297 - improve search perf in bpt by removing a deref
    
    Bug Description:  improve search perf in bpt by removing
    the derefence of the key cmp fn, instead we pass the fn ptr
    to the functions.
    
    Fix Description:  Pass the fn pointer to the search and lookup
    functions.
    
    https://pagure.io/389-ds-base/issue/49297
    
    Author: wibrown
    
    Review by: mreynolds (Thanks!)