Bump LLVM_PREBUILTS_VERSION

Test: n/a
Change-Id: I0bbbbb3892f3afbc3ca485f1801c757c0155f854
diff --git a/build-prebuilts.sh b/build-prebuilts.sh
index f8e2cba..3b54800 100755
--- a/build-prebuilts.sh
+++ b/build-prebuilts.sh
@@ -15,7 +15,7 @@
 # limitations under the License.
 
 export LLVM_BUILD_HOST_TOOLS=true
-export LLVM_PREBUILTS_VERSION=clang-r353983
+export LLVM_PREBUILTS_VERSION=clang-r353983b
 export LLVM_RELEASE_VERSION=9.0.1
 
 # FIXME: Workaround to build bionic versioner in the aosp/clang-tools branch.