evas_eet: Add Type Safety check

evas_eet: Add Type Safety check

Summary:
The Function _evas_canvas3d_eet_file_free(void) is referenced in  evas_model_load_file_eet()(file:evas_model_load_eet.c at line 122).
This call is  under condition
        if ((eet_file->mesh == NULL) || (eet_file->header == NULL)).
when  either eet_file->mesh or eet_file->header are NULL, dereference of the corresponding pointer in function "_evas_canvas3d_eet_file_free()"
will generate Segmentation Fault.

@fix

Reviewers: raster, Hermet, tasn, wonsik, spacegrapher, cedric, jpeg

Subscribers: singh.amitesh, sachin.dev, alok25, yashu21985, mvsovani, cedric

Differential Revision: https://phab.enlightenment.org/D3369