update error doc for code

Author: sinlov

fastEnDeCode_test.go

@@ -209,4 +209,4 @@ func TestAES_ECB_PKCS5_DecryptByte(t *testing.T) {
 	pStr := ByteArr2Str(deAES)
 	fmt.Println(pStr)
 	assert.Equal(t, str4AES, pStr, err)
-}
+}