selftests: bpf: Switch off timeout

Several bpf tests are interrupted by the default timeout of 45 seconds added
by commit 852c8cbf34d3 ("selftests/kselftest/runner.sh: Add 45 second
timeout per test"). In my case it was test_progs, test_tunnel.sh,
test_lwt_ip_encap.sh and test_xdping.sh.

There's not much value in having a timeout for bpf tests, switch it off.

Signed-off-by: Jiri Benc <[e-mail]>
Signed-off-by: Alexei Starovoitov <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/testing/selftests/bpf/settings

···
+timeout=0