Renable "html" indexing by default.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@78077 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/scan-build b/utils/scan-build
index 873f1a1..4b097a7 100755
--- a/utils/scan-build
+++ b/utils/scan-build
@@ -1029,7 +1029,7 @@
 my @AnalysesToRun;
 my $StoreModel;
 my $ConstraintsModel;
-my $OutputFormat;
+my $OutputFormat = "html";
 
 if (!@ARGV) {
   DisplayHelp();