drivers eth_native_linux: Avoid using ssize

ssize is a POSIX.1-2001 extension, which may or may
not be provided by the C library, or may be defined
to a different size in the host and embedded C library.

Two internal functions were returning ssize.
As these functions were just trampolines
into the same host API, which are already provided
by the native simulator let's just use those.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>
3 files changed