util-lib: move CONF_DIRS_NULSTR definition to def.h

After all, this is not some compiler or C magic, but something very
specific to how systemd works, hence let's move it into def.h, and out
of macro.h

src/basic/def.h

@@ -75,3 +75,18 @@
 
 #define NOTIFY_FD_MAX 768
 #define NOTIFY_BUFFER_MAX PIPE_BUF
+
+/* Return a nulstr for a standard cascade of configuration directories,
+ * suitable to pass to conf_files_list_nulstr or config_parse_many. */
+#define CONF_DIRS_NULSTR(n) \
+        "/etc/" n ".d\0" \
+        "/run/" n ".d\0" \
+        "/usr/local/lib/" n ".d\0" \
+        "/usr/lib/" n ".d\0" \
+        CONF_DIR_SPLIT_USR(n)
+
+#ifdef HAVE_SPLIT_USR
+#define CONF_DIR_SPLIT_USR(n) "/lib/" n ".d\0"
+#else
+#define CONF_DIR_SPLIT_USR(n)
+#endif

src/basic/macro.h

@@ -334,21 +334,6 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
                 _found;                                                 \
         })
 
-/* Return a nulstr for a standard cascade of configuration directories,
- * suitable to pass to conf_files_list_nulstr or config_parse_many. */
-#define CONF_DIRS_NULSTR(n) \
-        "/etc/" n ".d\0" \
-        "/run/" n ".d\0" \
-        "/usr/local/lib/" n ".d\0" \
-        "/usr/lib/" n ".d\0" \
-        CONF_DIR_SPLIT_USR(n)
-
-#ifdef HAVE_SPLIT_USR
-#define CONF_DIR_SPLIT_USR(n) "/lib/" n ".d\0"
-#else
-#define CONF_DIR_SPLIT_USR(n)
-#endif
-
 /* Define C11 thread_local attribute even on older gcc compiler
  * version */
 #ifndef thread_local