Reduce psnr_thresh in GFMaxPyrHeightTest

BUG=aomedia:2549

Change-Id: I42739e2f76ba965061d808644818610e961e5fd2
diff --git a/test/gf_max_pyr_height_test.cc b/test/gf_max_pyr_height_test.cc
index 56d3255..43cf09c 100644
--- a/test/gf_max_pyr_height_test.cc
+++ b/test/gf_max_pyr_height_test.cc
@@ -21,7 +21,7 @@
   int gf_max_pyr_height;
   double psnr_thresh;
 } kTestParams[] = {
-  { 0, 34.2 }, { 1, 34.40 }, { 2, 34.9 }, { 3, 35.1 }, { 4, 35.2 },
+  { 0, 34.2 }, { 1, 34.35 }, { 2, 34.9 }, { 3, 35.1 }, { 4, 35.2 },
 };
 
 // Compiler may decide to add some padding to the struct above for alignment,