libutils: DEBUG_* modes compile forever

I've seen these fixed before, so we compile the debug modes
now.

Bug: 244325464
Test: 'm libutils_test_compile'
Change-Id: I4271909e81893ad448bc46b8a3a567a84c40f8a3
diff --git a/libutils/Tokenizer.cpp b/libutils/Tokenizer.cpp
index 98dd2fd..c3ec165 100644
--- a/libutils/Tokenizer.cpp
+++ b/libutils/Tokenizer.cpp
@@ -21,9 +21,10 @@
 #include <sys/stat.h>
 #include <utils/Log.h>
 
+#ifndef DEBUG_TOKENIZER
 // Enables debug output for the tokenizer.
 #define DEBUG_TOKENIZER 0
-
+#endif
 
 namespace android {