net: sctp: remove TEST_FRAME ifdef

We do neither ship a test_frame.h, nor will this be compatible with
the 2.5 out-of-tree lksctp kernel test suite anyway. So remove this
artefact.

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