Remove internal link for mfcc_test

Remove a comment as it contains an internal link.

Change-Id: Ibaf8a8cd03607f4fadcff2bc8ba52a71896e30b9

samples/audio_prep/mfcc_test.cc

diff --git a/samples/audio_prep/mfcc_test.cc b/samples/audio_prep/mfcc_test.cc
index 659e90b..b801649 100644
--- a/samples/audio_prep/mfcc_test.cc
+++ b/samples/audio_prep/mfcc_test.cc
@@ -31,9 +31,6 @@
                                   0, 0, 209, 205, 181, 193, 182, 199, 209, 216,
                                   0, 0, 198, 194, 192, 204, 196, 201, 212, 223};
 
-// Golden value is derived from
-// http://google3/knowledge/cerebra/parrot/port/android/platform/
-// inference/daredevil/audio_prep/spectrogram_processor_test.cc
 TEST(MfccTest, AgreesWithGoldenValues) {
   // set parameters
   set_mfcc_params(&golden_params);