[llvm-cov] Move a check into a helper method (NFC)

llvm-svn: 274025
diff --git a/llvm/tools/llvm-cov/SourceCoverageView.cpp b/llvm/tools/llvm-cov/SourceCoverageView.cpp
index 4170fb4..b71a35f 100644
--- a/llvm/tools/llvm-cov/SourceCoverageView.cpp
+++ b/llvm/tools/llvm-cov/SourceCoverageView.cpp
@@ -74,7 +74,7 @@
 SourceCoverageView::createOutputStream(const CoverageViewOptions &Opts,
                                        StringRef Path, StringRef Extension,
                                        bool InToplevel) {
-  if (Opts.ShowOutputDirectory == "")
+  if (!Opts.hasOutputDirectory())
     return OwnedStream(&outs());
 
   return createFileInDirectory(Opts.ShowOutputDirectory,