net: sctp: get rid of SCTP_DBG_TSNS entirely

After having reworked the debugging framework, Neil and Vlad agreed to
get rid of the leftover SCTP_DBG_TSNS code for a couple of reasons:

We can use systemtap scripts to investigate these things, we now have
pr_debug() helpers that make life easier, and if we really need anything
else besides those tools, we will be forced to come up with something
better than we have there. Therefore, get rid of this ifdef debugging
code entirely for now.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>