Use -Werror in bionic

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: Ic68141a5c50880c485646e38349f94b866267bd9
diff --git a/libc/seccomp/Android.bp b/libc/seccomp/Android.bp
index a75aa65..b3707bc 100644
--- a/libc/seccomp/Android.bp
+++ b/libc/seccomp/Android.bp
@@ -16,6 +16,7 @@
         "mips64_global_policy.cpp",
     ],
     export_include_dirs: ["include"],
+    cflags: ["-Wall", "-Werror"],
     shared: {
         shared_libs: ["libbase"],
     },