Also print aq mode on EXPECT_GT(psnr) failure.

We print cpu moe when EXPECT_GT(psnr) fails. Since aq mode is also a
test parameter now, it'd be helpful to print the aq mode, too.

The new error message looks like:

  aom/test/rt_end_to_end_test.cc:118: Failure
  Expected: (psnr) > (GetPsnrThreshold()), actual: 35.1465 vs 36.8
  cpu used = 2 aq mode = 1

Change-Id: I84cca18619a8e05338b0a332a296526c1f017898

test/rt_end_to_end_test.cc

diff --git a/test/rt_end_to_end_test.cc b/test/rt_end_to_end_test.cc
index f09fff8..5123f23 100644
--- a/test/rt_end_to_end_test.cc
+++ b/test/rt_end_to_end_test.cc
@@ -115,7 +115,8 @@
 
     ASSERT_NO_FATAL_FAILURE(RunLoop(video.get()));
     const double psnr = GetAveragePsnr();
-    EXPECT_GT(psnr, GetPsnrThreshold()) << "cpu used = " << cpu_used_;
+    EXPECT_GT(psnr, GetPsnrThreshold())
+        << "cpu used = " << cpu_used_ << " aq mode = " << aq_mode_;
   }
 
   TestVideoParam test_video_param_;