eo: Fix unnecessary ERR logs with eo_debug

eo: Fix unnecessary ERR logs with eo_debug

efl_data_scope_safe_get() is often used to assert that an object is of a
certain type, but assuming it may be NULL or not of the required type.
This means that encountering an invalid type is an error handled by the
caller (we return NULL), and shouldn't print out extra ERR() logs.

This fixes issues with E run under eo_debug. E's code was safe as it's
using evas_object_smart_data_get() and verifies whether the returned
value is NULL (which is expected for a rectangle, for instance).

@fix