The hdr_offset member of the ARM Linux image header appears at
offset 0x3c, matching the PE/COFF spec's placement of the COFF
header offset in the MS-DOS header. We're currently off by four,
so fix that.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>