Kill some unnecessary calls to c_str().


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90084 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/UndefResultChecker.cpp b/lib/Analysis/UndefResultChecker.cpp
index ec12a98..acc86dd 100644
--- a/lib/Analysis/UndefResultChecker.cpp
+++ b/lib/Analysis/UndefResultChecker.cpp
@@ -74,8 +74,7 @@
          << BinaryOperator::getOpcodeStr(B->getOpcode())
          << "' expression is undefined";
     }
-    EnhancedBugReport *report = new EnhancedBugReport(*BT, 
-                                                    OS.str().str().c_str(), N);
+    EnhancedBugReport *report = new EnhancedBugReport(*BT, OS.str(), N);
     if (Ex) {
       report->addRange(Ex->getSourceRange());
       report->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, Ex);