Fixed error handling

src/main.rs

@@ -4,6 +4,6 @@ fn main() {
     println!("Converting test.webp to test.png.");
     let img_raw = ImageReader::open("test.webp").expect("Failed to load test.webp.")
     let img = img_raw.decode().expect("Failed to decode the image.");
-    img.save("test.png").("Failed to save test.png.");
+    img.save("test.png").expect("Failed to save test.png.");
     println!("Done.");
 }