Factor CHECKED out of DEBUG so it can be set seperatly

Suggested-by: Matt Wolenetz <wolenetz@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/flacdsp.c

@@ -45,7 +45,7 @@
 
 // For debuging we use signed operations so overflows can be detected (by ubsan)
 // For production we use unsigned so there are no undefined operations
-#ifdef DEBUG
+#ifdef CHECKED
 #define SUINT   int
 #else
 #define SUINT   unsigned

libavutil/internal.h

@@ -30,6 +30,10 @@
 #    define NDEBUG
 #endif
 
+#if defined(DEBUG) && !defined(CHECKED)
+#    define CHECKED
+#endif
+
 #include <limits.h>
 #include <stdint.h>
 #include <stddef.h>