LibCompress: Return Optional from decompress_all method.

Author: https://github.com/asynts
Commit: 4af8eea56f
Pull-request: https://github.com/SerenityOS/serenity/pull/3455

Libraries/LibCompress/Zlib.cpp

@@ -55,11 +55,17 @@ Zlib::Zlib(ReadonlyBytes data)
     m_data_bytes = data.slice(2, data.size() - 2 - 4);
 }
 
-ByteBuffer Zlib::decompress()
+Optional<ByteBuffer> Zlib::decompress()
 {
     return DeflateDecompressor::decompress_all(m_data_bytes);
 }
 
+Optional<ByteBuffer> Zlib::decompress_all(ReadonlyBytes bytes)
+{
+    Zlib zlib { bytes };
+    return zlib.decompress();
+}
+
 u32 Zlib::checksum()
 {
     if (!m_checksum) {