chore: remove repetitive words (#946)

Signed-off-by: kindhuge <huangpengfei@outlook.com>

Author: kindhuge

internal/snapref/encode_other.go

@@ -51,7 +51,7 @@ 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

s2/writer.go

@@ -937,7 +937,7 @@ func WriterUncompressed() WriterOption {
 
 // WriterBlockSize allows to override the default block size.
 // Blocks will be this size or smaller.
-// Minimum size is 4KB and and maximum size is 4MB.
+// Minimum size is 4KB and maximum size is 4MB.
 //
 // Bigger blocks may give bigger throughput on systems with many cores,
 // and will increase compression slightly, but it will limit the possible