Try fix the usage of fd().

{{project-name}}/src/main.rs

@@ -123,11 +123,11 @@ async fn main() -> Result<(), anyhow::Error> {
     program.attach(cgroup)?;
     {%- when "sk_msg" -%}
     let sock_map: SockHash::<_, SockKey> = bpf.map("{{sock_map}}").unwrap().try_into()?;
-    let map_fd = sock_map.fd()?;
+    let map_fd = sock_map.fd();
 
     let prog: &mut SkMsg = bpf.program_mut("{{crate_name}}").unwrap().try_into()?;
     prog.load()?;
-    prog.attach(map_fd.into())?;
+    prog.attach(map_fd)?;
     // insert sockets to the map using sock_map.insert here, or from a sock_ops program
     {%- when "xdp" -%}
     let program: &mut Xdp = bpf.program_mut("{{crate_name}}").unwrap().try_into()?;