Remove useless format!

Author: MikailBag

src/minion-ffi/build.rs

@@ -1,6 +1,6 @@
 fn main() {
     let crate_root = std::env::var("CARGO_MANIFEST_DIR").unwrap();
-    let out_file = format!("../../target/minion-ffi.h"); //TODO better path
+    let out_file = "../../target/minion-ffi.h".to_string(); //TODO better path
     cbindgen::generate(crate_root)
         .expect("was unable to generate bindings")
         .write_to_file(out_file);