Fix formatting (#263)

src/decoder/image.rs

@@ -378,11 +378,9 @@ impl Image {
             CompressionMethod::None => Box::new(reader),
             CompressionMethod::LZW => {
                 Box::new(LZWReader::new(reader, usize::try_from(compressed_length)?))
-            },
+            }
             #[cfg(feature = "zstd")]
-            CompressionMethod::ZSTD => {
+            CompressionMethod::ZSTD => Box::new(zstd::Decoder::new(reader)?),
-                Box::new(zstd::Decoder::new(reader)?)
-            },
             CompressionMethod::PackBits => Box::new(PackBitsReader::new(reader, compressed_length)),
             CompressionMethod::Deflate | CompressionMethod::OldDeflate => {
                 Box::new(DeflateReader::new(reader))