Simplify gcd example: remove unnecessary clone

crates/api/examples/gcd.rs

@@ -58,7 +58,7 @@ fn main() -> Result<()> {
     let instance = Instance::new(&store, &module, &[])?;
 
     // Invoke `gcd` export
-    let gcd = instance.exports()[gcd_index].func().expect("gcd").clone();
+    let gcd = instance.exports()[gcd_index].func().expect("gcd");
     let result = gcd
         .borrow()
         .call(&[Val::from(6i32), Val::from(27i32)])