Use -Werror in bionic/tests

* Should not use -Wno-error

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: I92552b0d9860835216500c4f57574cd2928b24f1
diff --git a/tests/Android.bp b/tests/Android.bp
index 742f44a..66d9aec 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -194,7 +194,6 @@
 cc_defaults {
     name: "bionic_fortify_tests_defaults",
     cflags: [
-        "-Wno-error",
         "-U_FORTIFY_SOURCE",
     ],
     srcs: ["fortify_test_main.cpp"],