[Darwine] Non elf elf_read_wine_loader_dbg_info fix

[Pierre d'H. <ste...@fr...>]

Hi!

This patch enables dbghelp compilation on Darwin and more generally on 
non-Elf host. There was a difference between the prototype and the 
implementation.

Pierre

ChangeLog:
elf_read_wine_loader_dbg_info fix for non elf host.