encode_other.go: remove repetitive word

encode_other.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build (!amd64 && !arm64) || appengine || !gc || noasm
 // +build !amd64,!arm64 appengine !gc noasm
 
 package snappy
@@ -51,7 +52,7 @@ func emitCopy(dst []byte, offset, length int) int {
 	i := 0
 	// The maximum length for a single tagCopy1 or tagCopy2 op is 64 bytes. The
 	// threshold for this loop is a little higher (at 68 = 64 + 4), and the
-	// length emitted down below is is a little lower (at 60 = 64 - 4), because
+	// length emitted down below is a little lower (at 60 = 64 - 4), because
 	// it's shorter to encode a length 67 copy as a length 60 tagCopy2 followed
 	// by a length 7 tagCopy1 (which encodes as 3+2 bytes) than to encode it as
 	// a length 64 tagCopy2 followed by a length 3 tagCopy2 (which encodes as