[DCCP] ackvec: Ditch dccpav_buf_len

Simplifying the code a bit as we're always using DCCP_MAX_ACKVEC_LEN.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
4 files changed