AV1 RT: Modify PSNR threshold for reduced TX search.

BUG=aomedia:2555

Change-Id: If2db5a1bbb993f3152880c6a88d688b53c4504ff
diff --git a/test/rt_end_to_end_test.cc b/test/rt_end_to_end_test.cc
index dd84f60..eca47c7 100644
--- a/test/rt_end_to_end_test.cc
+++ b/test/rt_end_to_end_test.cc
@@ -31,7 +31,7 @@
 std::unordered_map<std::string,
                    std::unordered_map<int, std::unordered_map<int, double>>>
     kPsnrThreshold = { { "park_joy_90p_8_420.y4m",
-                         { { 6, { { 0, 35.5 }, { 3, 36.3 } } },
+                         { { 6, { { 0, 35.4 }, { 3, 36.3 } } },
                            { 7, { { 0, 34.9 }, { 3, 35.8 } } },
                            { 8, { { 0, 35.0 }, { 3, 36.0 } } } } },
                        { "paris_352_288_30.y4m",