Improve error traces about ROHC packet and output buffer.
Improve error traces about ROHC packet and output buffer.

Improve error traces to get more information about ROHC packets of length
greater than the output buffer.

didier-barvaux/rohc,didier-barvaux/rohc,didier-barvaux/rohc,didier-barvaux/rohc,didier-barvaux/rohc