dbghelp: Match the crc for debug link files in elf_locate_debug_link so that we get the correct debug file before trying to parse it.

[Eric Pouech]

Robert Shearman a écrit :
>
> Keep the debuglink elf_file_map mapped until after 
> elf_new_public_symbols is called, otherwise we could use unmapped memory.

this is still not the full valid solution... what should be done is: 
when we search for a given section, we should look first in the original 
.so, then, if not found, in the .gnu_debuglink one...
your patch only covers the case where all relevant information is to be 
found in the .gnu_debuglink file, which is not guaranteed
A+