Remove dead error check.

The io.ReadFull function always returns an error if the full payload can't
be read, so there is no reason to further check if the payload length
matches after a successful read.

message.go

@@ -117,7 +117,7 @@ type messageHeader struct {
 	checksum [4]byte    // 4 bytes
 }
 
-// readMessageHeader reads a bitcoin messager header from r.
+// readMessageHeader reads a bitcoin message header from r.
 func readMessageHeader(r io.Reader) (*messageHeader, error) {
 	var command [commandSize]byte
 
@@ -195,15 +195,10 @@ func readMessage(r io.Reader, pver uint32, hdr *messageHeader) (Message, []byte,
 
 	// Read payload.
 	payload := make([]byte, hdr.length)
-	n, err := io.ReadFull(r, payload)
+	_, err = io.ReadFull(r, payload)
 	if err != nil {
 		return nil, nil, err
 	}
-	if uint32(n) != hdr.length {
-		str := "readMessage: failed to read payload - Read %v " +
-			"bytes, but payload size is %v bytes."
-		return nil, nil, fmt.Errorf(str, n, hdr.length)
-	}
 
 	// Test checksum.
 	checksum := DoubleSha256(payload)[0:4]