selftests/bpf: Fix bpf_prog_detach2 usage in test_lirc_mode2

Commit e9fc3ce ("libbpf: Streamline error reporting for high-level
APIs") redefined the way that bpf_prog_detach2() returns. Therefore, adapt
the usage in test_lirc_mode2_user.c.

Signed-off-by: Ricardo B. Marlière <[email protected]>

Author: rbmarliere

tools/testing/selftests/bpf/test_lirc_mode2_user.c

@@ -74,7 +74,7 @@ int main(int argc, char **argv)
 
 	/* Let's try detach it before it was ever attached */
 	ret = bpf_prog_detach2(progfd, lircfd, BPF_LIRC_MODE2);
-	if (ret != -1 || errno != ENOENT) {
+	if (ret != -ENOENT) {
 		printf("bpf_prog_detach2 not attached should fail: %m\n");
 		return 1;
 	}