[analyzer] [tests] Fix a typo in analyzer testing script.

Incorrect option instance construction.

llvm-svn: 324946
diff --git a/clang/utils/analyzer/SATestBuild.py b/clang/utils/analyzer/SATestBuild.py
index 2becaa0..7ec87e4 100755
--- a/clang/utils/analyzer/SATestBuild.py
+++ b/clang/utils/analyzer/SATestBuild.py
@@ -567,7 +567,7 @@
 
         PatchedSourceDirPath = os.path.join(Dir, PatchedSourceDirName)
         Opts, Args = CmpRuns.generate_option_parser().parse_args(
-            ["", PatchedSourceDirPath])
+            ["--rootA", "", "--rootB", PatchedSourceDirPath])
         # Scan the results, delete empty plist files.
         NumDiffs, ReportsInRef, ReportsInNew = \
             CmpRuns.dumpScanBuildResultsDiff(RefDir, NewDir, Opts, False)