[sanitizer] Always clobber if unexpected svn/git checkout exists

git-svn-id: https://llvm.org/svn/llvm-project/zorg/trunk@370238 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/zorg/buildbot/builders/sanitizers/buildbot_functions.sh b/zorg/buildbot/builders/sanitizers/buildbot_functions.sh
index 09132ac..39f048f 100755
--- a/zorg/buildbot/builders/sanitizers/buildbot_functions.sh
+++ b/zorg/buildbot/builders/sanitizers/buildbot_functions.sh
@@ -11,6 +11,15 @@
 }
 
 function clobber {
+  # Clobber if USE_GIT was changed
+  local clobber_if_exists=llvm-project
+  if [[ "$USE_GIT" != "0" ]]; then
+    clobber_if_exists=llvm
+  fi
+  if [[ -d $clobber_if_exists ]]; then
+    BUILDBOT_CLOBBER=1
+  fi
+
   if [ "$BUILDBOT_CLOBBER" != "" ]; then
     echo @@@BUILD_STEP clobber@@@
     rm -rf svn_checkout llvm llvm-project llvm_build0 ${CLOBBER:-}