Avoid reader/writer duplication in every encoder/decoder
diff --git a/common/rfb/ZRLEEncoder.cxx b/common/rfb/ZRLEEncoder.cxx
index 7e00fad..df7cfbd 100644
--- a/common/rfb/ZRLEEncoder.cxx
+++ b/common/rfb/ZRLEEncoder.cxx
@@ -46,8 +46,8 @@
 #undef CPIXEL
 #undef BPP
 
-ZRLEEncoder::ZRLEEncoder(SMsgWriter* writer_)
-  : writer(writer_), zos(0,0,zlibLevel), mos(129*1024)
+ZRLEEncoder::ZRLEEncoder(SMsgWriter* writer)
+  : Encoder(writer), zos(0,0,zlibLevel), mos(129*1024)
 {
 }