[sanitizer] Fix buildbot_update call

It should forward to buildbot_update_git internally according USE_GIT

git-svn-id: https://llvm.org/svn/llvm-project/zorg/trunk@370119 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/zorg/buildbot/builders/sanitizers/buildbot_fast.sh b/zorg/buildbot/builders/sanitizers/buildbot_fast.sh
index 5c219c4..3c8811c 100755
--- a/zorg/buildbot/builders/sanitizers/buildbot_fast.sh
+++ b/zorg/buildbot/builders/sanitizers/buildbot_fast.sh
@@ -40,7 +40,7 @@
 CMAKE_COMMON_OPTIONS="$CMAKE_COMMON_OPTIONS -DLLVM_ENABLE_ASSERTIONS=ON"
 
 echo @@@BUILD_STEP update@@@
-buildbot_update_git
+buildbot_update
 
 # Stage 2 / Memory Sanitizer