Fixed error handling

src/main.rs

@@ -2,7 +2,8 @@ use image::io::Reader as ImageReader;
 
 fn main() {
     println!("Converting test.webp to test.png.");
-    let img = ImageReader::open("test.webp")?.decode()?;
-    img.save("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.");
     println!("Done.");
 }