fix: Address clippy error regarding zombie child process (#1053)

https://rust-lang.github.io/rust-clippy/master/index.html#zombie_processes

src-tauri/src/northstar/mod.rs

@@ -214,10 +214,11 @@ pub fn launch_northstar(
         let ns_exe_path = format!("{}/NorthstarLauncher.exe", game_install.game_path);
         let ns_profile_arg = format!("-profile={}", game_install.profile);
 
-        let _output = std::process::Command::new("C:\\Windows\\System32\\cmd.exe")
+        let mut output = std::process::Command::new("C:\\Windows\\System32\\cmd.exe")
             .args(["/C", "start", "", &ns_exe_path, &ns_profile_arg])
             .spawn()
             .expect("failed to execute process");
+        output.wait().expect("failed waiting on child process");
         return Ok("Launched game".to_string());
     }