Fix compile of programs/winedbg/elf.c on NetBSD 1.6

[Eric Pouech]

Yorick Hardy a écrit :
> Not to worry, I am now more confused than ever :-).
> By the way, what is STN_UNDEF for ?
it's used as an index in the Elf32_Sym array to identify the undefined 
symbol, whereas SHN_UNDEF is a potential value of Elf32_Sym.st_shndx 
(which is the section in which the symbol is defined), and refers to the 
undefined section (for undefined symbols)

A+