Fix for previous commit, which caused many compiler warnings/errors
about addresses of volatile objects passed as function arguments
as non-volatile pointers.
* freetype2/include/freetype/internal/ftvalid.h: Make
FT_Validator typedef a pointer to a volatile object.
* freetype2/src/gxvalid/gxvmod.c (gxv_load_table): Make function
argument `table' a pointer to a volatile object.
* freetype2/src/otvalid/otvmod.c (otv_load_table): Make function
argument `table' a pointer to a volatile object.
088e44e877