[llvm-cov] Fix a lifetime issue

This fixes an issue where a std::string was moved to a constructor
which accepted a StringRef.

llvm-svn: 312816
diff --git a/llvm/tools/llvm-cov/CodeCoverage.cpp b/llvm/tools/llvm-cov/CodeCoverage.cpp
index b99a418..0e3d67e5 100644
--- a/llvm/tools/llvm-cov/CodeCoverage.cpp
+++ b/llvm/tools/llvm-cov/CodeCoverage.cpp
@@ -42,6 +42,7 @@
 using namespace coverage;
 
 void exportCoverageDataToJson(const coverage::CoverageMapping &CoverageMapping,
+                              const CoverageViewOptions &Options,
                               raw_ostream &OS);
 
 namespace {
@@ -932,7 +933,7 @@
     return 1;
   }
 
-  exportCoverageDataToJson(*Coverage.get(), outs());
+  exportCoverageDataToJson(*Coverage.get(), ViewOpts, outs());
 
   return 0;
 }