Typo fixes for doc_test.go and cbc_hmac.go

cipher/cbc_hmac.go

@@ -150,7 +150,7 @@ func (ctx *cbcAEAD) computeAuthTag(aad, nonce, ciphertext []byte) []byte {
 	return hmac.Sum(nil)[:ctx.authtagBytes]
 }
 
-// resize ensures the the given slice has a capacity of at least n bytes.
+// resize ensures that the given slice has a capacity of at least n bytes.
 // If the capacity of the slice is less than n, a new slice is allocated
 // and the existing data will be copied.
 func resize(in []byte, n uint64) (head, tail []byte) {

doc_test.go

@@ -63,7 +63,7 @@ func Example_jWE() {
 	}
 
 	// Now we can decrypt and get back our original plaintext. An error here
-	// would indicate the the message failed to decrypt, e.g. because the auth
+	// would indicate that the message failed to decrypt, e.g. because the auth
 	// tag was broken or the message was tampered with.
 	decrypted, err := object.Decrypt(privateKey)
 	if err != nil {
@@ -109,7 +109,7 @@ func Example_jWS() {
 	}
 
 	// Now we can verify the signature on the payload. An error here would
-	// indicate the the message failed to verify, e.g. because the signature was
+	// indicate that the message failed to verify, e.g. because the signature was
 	// broken or the message was tampered with.
 	output, err := object.Verify(&privateKey.PublicKey)
 	if err != nil {