Update key_io.cpp

src/key_io.cpp

@@ -337,7 +337,7 @@ libzcash::ViewingKey DecodeViewingKey(const std::string& str)
     return libzcash::InvalidEncoding();
 }
 
-std::string KeyIO::EncodeIVK(const libzcash::SaplingIncomingViewingKey& ivk)
+std::string EncodeIVK(const libzcash::SaplingIncomingViewingKey& ivk)
 {
     CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
     ss << ivk;
@@ -353,7 +353,7 @@ std::string KeyIO::EncodeIVK(const libzcash::SaplingIncomingViewingKey& ivk)
     return ret;
 }
 
-libzcash::SaplingIncomingViewingKey KeyIO::DecodeIVK(const std::string& str)
+libzcash::SaplingIncomingViewingKey DecodeIVK(const std::string& str)
 {
     std::vector<unsigned char> data;
     auto bech = bech32::Decode(str);