sctp: remove the useless check in sctp_renege_events

sctp: remove the useless check in sctp_renege_events

Remove the 'if (chunk)' check in sctp_renege_events for idata process,
as all renege commands are generated in sctp_eat_data and it can't be
NULL.

The same thing we already did for common data in sctp_ulpq_renege.

Fixes: 94014e8d871a ("sctp: implement renege_events for sctp_stream_interleave")
Signed-off-by: Xin Long <[email protected]>
Acked-by: Marcelo Ricardo Leitner <[email protected]>
Acked-by: Neil Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>