Remove stray output to stdout from tests (#4816)

diff --git a/test/opt/scalar_analysis.cpp b/test/opt/scalar_analysis.cpp
index 598d8c7..df2aa8f 100644
--- a/test/opt/scalar_analysis.cpp
+++ b/test/opt/scalar_analysis.cpp
@@ -1202,7 +1202,6 @@
   EXPECT_EQ(phis.size(), 2u);
   SENode* phi_node_1 = analysis.AnalyzeInstruction(phis[0]);
   SENode* phi_node_2 = analysis.AnalyzeInstruction(phis[1]);
-  phi_node_1->DumpDot(std::cout, true);
   EXPECT_NE(phi_node_1, nullptr);
   EXPECT_NE(phi_node_2, nullptr);