Return -1 in the error case from read_bandwidth_usage.

svn:r19367

ChangeLog

@@ -1,3 +1,9 @@
+Changes in version 0.2.1.15??? - ????-??-??
+  o Minor bugfixes:
+    - Actually return -1 in the error case for read_bandwidth_usage. Bug
+      was harmless, we currently don't care for the return value anywhere.
+      Bugfix on 0.2.0.9-alpha.
+
 Changes in version 0.2.1.14-rc - 2009-04-12
   o Major features:
     - Clients replace entry guards that were chosen more than a few months

src/or/hibernate.c

@@ -580,7 +580,7 @@ read_bandwidth_usage(void)
   }
 
   if (!state)
-    return 0;
+    return -1;
 
   /* Okay; it looks like the state file is more up-to-date than the
    * bw_accounting file, or the bw_accounting file is nonexistant,