Tweak options comment

Signed-off-by: Matt Lord <[email protected]>

go/mysql/binlog_event_compression.go

@@ -367,7 +367,7 @@ func (dp *decoderPool) Get(reader io.Reader) (*zstd.Decoder, error) {
 		}
 	} else {
 		// Use the minimum amount of memory we can in processing the transaction by
-		// setting lowMem to true and limiting the window concurrency to 1 so that
+		// setting lowMem to true and limiting the decoder concurrency to 1 so that
 		// there's no async decoding of multiple windows or blocks.
 		d, err := zstd.NewReader(nil, zstd.WithDecoderLowmem(true), zstd.WithDecoderConcurrency(1))
 		if err != nil { // Should only happen e.g. due to ENOMEM