crash_dump: fix warnings, turn on -Werror.

Test: mma
Change-Id: I0722fef7b513be976cbbe89f73e8bb7138a80442
diff --git a/debuggerd/Android.bp b/debuggerd/Android.bp
index af84be9..b385ea5 100644
--- a/debuggerd/Android.bp
+++ b/debuggerd/Android.bp
@@ -3,7 +3,7 @@
     cflags: [
         "-Wall",
         "-Wextra",
-        "-Wno-error",
+        "-Werror",
         "-Wno-nullability-completeness",
         "-Os",
     ],