src: fix validation of negative offset to avoid abort

Fixes: https://github.com/nodejs/node/issues/24640


Signed-off-by: James M Snell <jasnell@gmail.com>

PR-URL: https://github.com/nodejs/node/pull/38421


Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Nitzan Uziely <linkgoron@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>