We are returning EINVAL from content format write ops when an object
field definition is not found (an optional field which is not
implemented). Instead, return ENOENT which lets the LwM2M engine
know to send ZOAP_RESPONSE_CODE_NOT_FOUND to the LwM2M server at the
end of handle_request().
NOTE: This behavior is not correct when we call the writer right after
a CREATE operation where the data is assigned to resources for the
first time. This case will be handled in a follow-up patch once we're
able to distinguish between a WRITE and a CREATE in the write op
handler.
Signed-off-by: Michael Scott <michael.scott@linaro.org>
75016c7b97