[PATCH bpf-next] bpf: fix build failure for kernel/trace/bpf_trace.c with CONFIG_NET=n

[Yonghong Song <yhs@xxxxxx>]

When CONFIG_NET is not defined, I hit the following build error:
    kernel/trace/bpf_trace.o:(.rodata+0x110): undefined reference to `bpf_prog_test_run_raw_tp'

Commit 1b4d60ec162f ("bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint")
added test_run support for raw_tracepoint in /kernel/trace/bpf_trace.c.
But the test_run function bpf_prog_test_run_raw_tp is defined in
net/bpf/test_run.c, only available with CONFIG_NET=y.

Adding a CONFIG_NET guard for
    .test_run = bpf_prog_test_run_raw_tp;
fixed the above build issue.

Fixes: 1b4d60ec162f ("bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint")
Cc: Song Liu <songliubraving@xxxxxx>
Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
 kernel/trace/bpf_trace.c | 2 ++
 1 file changed, 2 insertions(+)

Note: I found the above issue when I reviewed the following patch:
      https://lore.kernel.org/bpf/fcf3f659-027e-517f-086d-deb3ad33d953@xxxxxx/T

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index a136a6a63a71..a2a4535b6277 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1780,7 +1780,9 @@ const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
 };
 
 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
+#ifdef CONFIG_NET
 	.test_run = bpf_prog_test_run_raw_tp,
+#endif
 };
 
 const struct bpf_verifier_ops tracing_verifier_ops = {
-- 
2.24.1