eeze_net: fix a potentional memory leak case

Summary:
if net equals zero and device has allocated properly at the same time, memory leaks.
this patch fixes it.

Reviewers: Hermet, bu5hm4n, zmike

Reviewed By: Hermet

Subscribers: vtorri, cedric, reviewers, committers

Tags: efl

Differential Revision: https://phab.enlightenment.org/D12221