nlist: Fix unbounded malloc() calls

nlist: Fix unbounded malloc() calls

There are a couple of malloc() calls with unbounded size arguments,
coming from the parsed file. We need to make sure the size is not
larger than the file being parsed, otherwise we might end up with
out of memory conditions.

Reported-by: Daniel Hodson <daniel@elttam.com.au>
Signed-off-by: Guillem Jover <guillem@hadrons.org>