example: Add TCP header modification example

- add  example to workspace
- exit program when attach fails

Author: ThisSeanZhang

Cargo.lock

@@ -8,6 +8,7 @@ members = [
   "examples/runqslower",
   "examples/tc_port_whitelist",
   "examples/tcp_ca",
+  "examples/tcp_option",
   "examples/tproxy",
 ]
 resolver = "2"

Cargo.toml

@@ -136,7 +136,8 @@ fn main() -> Result<()> {
             println!("BPF Attached Successfully!");
         }
         _ => {
-            println!("Failed to Attach BPF, Reason: {:?}", Error::last_os_error());
+            println!("Failed to Attach BPF, Reason: ");
+            return Err(Error::last_os_error().into());
         }
     };