fix typo in pipeline.cc

TBR=bmeurer@chromium.org

BUG=

Review URL: https://codereview.chromium.org/743603003

Cr-Commit-Position: refs/heads/master@{#25413}

src/compiler/pipeline.cc

@@ -638,7 +638,7 @@ struct VerifyGraphPhase {
 
 void Pipeline::BeginPhaseKind(const char* phase_kind_name) {
   if (data_->pipeline_statistics() != NULL) {
-    data_->pipeline_statistics()->BeginPhaseKind("phase_kind_name");
+    data_->pipeline_statistics()->BeginPhaseKind(phase_kind_name);
   }
 }