Revert "loplugin: cstylecast"

The change was broken. Luckily MSVC noticed: sw\inc\doc.hxx(1707) :
warning C4717: 'SwDoc::GetNumberFormatter' : recursive on all control
paths, function will cause runtime stack overflow.

This reverts commit 7ca3303aaadd20dcc1d6e08bdeba38021cbec4bb.