Fix MSVC errors in tbprobe.cpp

Default template parameters values and recursive functions do not play well
together. Fix for below errors that showed up after updating to latest MSVC.

````
tbprobe.cpp(1156): error C2672:
    'search': no matching overloaded function found

tbprobe.cpp(1198): error C2783:
  'Tablebases::WDLScore `anonymous-namespace'::search(Position &,Tablebases::ProbeState *)':
could not deduce template argument for 'CheckZeroingMoves'

````

Closes https://github.com/official-stockfish/Stockfish/pull/1594

No functional change.