Potential bug in example code

[SebastianSchildt]

There lurks a potentially nasty bug in the example in the toplevel Readme

Open1722/README.md

Lines 148 to 149 in 7fe06a3

	Avtp_Lin_t lin;
	uint8_t linPayload[LIN_PAYLOAD_LEN];

C standard does not guarantee that uint8_t linPayload[LIN_PAYLOAD_LEN]; follows in memory after Avtp_Lin_t lin; there might be gaps in between due to alignment. Thus the memcpy in the end may copy an invalid frame.

I think either we change the example using a more robust pattern, or at least warn about this (there are some non-standard tags in some compilers to force it to create packed structs)

[adriaan-niess]

My proposal would be to add a __attribute__((packed)) even though it might not be supported by all compilers.