Misinterpreted FILE note for 32bit core files in readelf

[Markus Engel]

For 32bit core files, the FILE note is misinterpreted (tested in Version 
0.158 and git with readelf being a 64 and 32 bit binary), here is an 
example output:
CORE                  72  FILE
    2 files:
      00000000-080eb000 36d67b6ccd38000 135180288    gel/z/a.out
    Not enough data in NT_FILE note.
In readelf.c:handle_file_note, count and page_size are already 
interpreted as 64 bit values, which advances ptr by 2*8 instead of 2*4.
I traced this further to buf_read_ulong, where u has a size of 8, which 
is given to convert, returning data + 8.
Besides tracing these things I don't know how to fix it, mostly because 
I don't know where exactly things go an unintended way :)

Regards,
Markus