fix fig_input_method

Author: grant0417

crates/fig_input_method/src/main.rs

@@ -3,11 +3,14 @@ mod imk;
 #[cfg(target_os = "macos")]
 mod macos;
 
+#[cfg(not(target_os = "macos"))]
+use std::process::ExitCode;
+
 #[cfg(target_os = "macos")]
 pub use macos::main;
 
 #[cfg(not(target_os = "macos"))]
-fn main() -> std::process::ExitCode {
+fn main() -> ExitCode {
     println!("Fig input method is only supported on macOS");
-    std::process::ExitCode
+    ExitCode::FAILURE
 }