[llvm-exegesis][NFC] Revert rL343682 "Fix unused variable warning".

That was not the proper fix: the variable is used in debug mode.

llvm-svn: 343685

llvm/tools/llvm-exegesis/lib/Analysis.cpp

@@ -142,7 +142,7 @@ void Analysis::printInstructionRowCsv(const size_t PointId,
 
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
   const llvm::MCSchedClassDesc *const SCDesc =
-      SchedModel.getSchedClassDesc(SchedClassId);
+      SubtargetInfo_->getSchedModel().getSchedClassDesc(SchedClassId);
   writeEscaped<kEscapeCsv>(OS, SCDesc->Name);
 #else
   OS << SchedClassId;