Fix miscellaneous compiler warnings.
* freetype2/include/freetype/internal/ftobjs.h: close
comment with `*/' to avoid `/* in comment' compiler warning.
* freetype2/src/base/ftdbgmem.c (ft_mem_table_get_source): Turn
cast `(FT_UInt32)(void*)' into `(FT_UInt32)(FT_PtrDist)(void*)'
since on 64-bit platforms void* is larger than FT_UInt32.
* freetype2/src/base/ftobjs.c (t_validator_error): cast
away volatileness of argument to ft_longjmp. Spotted by
Werner `Putzfrau' Lemberg.
* freetype2/src/bdf/bdflib.c (bdf_load_font): initialize
local variable `lineno'.
* freetype2/src/gxvalid/gxvmod.c (classic_kern_validate):
mark local variable `error' volatile.