selftests/bpf: mark verifier test that uses bpf_trace_printk as BPF_PROG_TYPE_TRACEPOINT

We don't have this helper if the kernel was compiled without
CONFIG_BPF_EVENTS. Setting prog_type to BPF_PROG_TYPE_TRACEPOINT
let's verifier correctly skip this test based on the missing
prog_type support in the kernel.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/testing/selftests/bpf/verifier/unpriv.c

@@ -76,6 +76,7 @@
 	.errstr_unpriv = "unknown func bpf_trace_printk#6",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
 },
 {
 	"unpriv: pass pointer to helper function",