selftests/bpf: Don't use deprecated libbpf APIs

Remove all uses of bpf_program__title() and
bpf_program__find_program_by_title().

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

tools/testing/selftests/bpf/flow_dissector_load.h

···
 	if (ret)
 		return ret;
 
-	main_prog = bpf_object__find_program_by_title(*obj, section_name);
+	main_prog = NULL;
+	bpf_object__for_each_program(prog, *obj) {
+		if (strcmp(section_name, bpf_program__section_name(prog)) == 0) {
+			main_prog = prog;
+			break;
+		}
+	}
 	if (!main_prog)
 		return -1;
 

tools/testing/selftests/bpf/prog_tests/reference_tracking.c

···
 		const char *title;
 
 		/* Ignore .text sections */
-		title = bpf_program__title(prog, false);
+		title = bpf_program__section_name(prog);
 		if (strstr(title, ".text") != NULL)
 			continue;
 

tools/testing/selftests/bpf/test_socket_cookie.c

···
 	}
 
 	bpf_object__for_each_program(prog, pobj) {
-		prog_name = bpf_program__title(prog, /*needs_copy*/ false);
+		prog_name = bpf_program__section_name(prog);
 
 		if (libbpf_attach_type_by_name(prog_name, &attach_type))
 			goto err;