[sanitizer] Fix ubsan build

Author: vitalybuka

zorg/buildbot/builders/sanitizers/buildbot_functions.sh

@@ -274,7 +274,7 @@ function build_stage2 {
   elif [ "$sanitizer_name" == "ubsan" ]; then
     export UBSAN_OPTIONS="external_symbolizer_path=${llvm_symbolizer_path}:print_stacktrace=1"
     llvm_use_sanitizer="Undefined"
-    fsanitize_flag="-fsanitize=address,undefined -fno-sanitize-recover=all"
+    fsanitize_flag="-fsanitize=undefined -fno-sanitize-recover=all"
     # FIXME: After switching to LLVM_ENABLE_RUNTIMES, vptr has infitine
     # recursion.
     fno_sanitize_flag+=" -fno-sanitize=vptr"