selftests/bpf: Test a BPF CC implementing the unsupported get_info()

selftests/bpf: Test a BPF CC implementing the unsupported get_info()

Test whether a TCP CC implemented in BPF providing get_info() is
rejected correctly. get_info() is unsupported in a BPF CC. The check for
required functions in a BPF CC has moved, this test ensures unsupported
functions are still rejected correctly.

Signed-off-by: Jörn-Thorben Hinz <jthinz@mailbox.tu-berlin.de>
Reviewed-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220622191227.898118-6-jthinz@mailbox.tu-berlin.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>