Revert "Revert "Add hidserv-stats filname to our sandbox filter""

This reverts commit 5446cb8d3d536e9bc737de6d9286bd4b4b185661.

The underlying revert was done in 0.2.6, since we aren't backporting
seccomp2 loosening fixes to 0.2.6.  But the fix (for 17354) already
went out in 0.2.7.4-rc, so we shouldn't revert it in 0.2.7.

changes/bug17354

@@ -0,0 +1,4 @@
+  o Minor bugfixes (sandbox):
+    - Add the "hidserv-stats" filename to our sandbox filter for the
+      HiddenServiceStatistics option to work properly. Fixes bug 17354;
+      bugfix on tor-0.2.6.2-alpha~54^2~1. Patch from David Goulet.

src/or/main.c

@@ -3200,6 +3200,7 @@ sandbox_init_filter(void)
     RENAME_SUFFIX2("stats", "exit-stats", ".tmp");
     RENAME_SUFFIX2("stats", "buffer-stats", ".tmp");
     RENAME_SUFFIX2("stats", "conn-stats", ".tmp");
+    RENAME_SUFFIX2("stats", "hidserv-stats", ".tmp");
     RENAME_SUFFIX("hashed-fingerprint", ".tmp");
     RENAME_SUFFIX("router-stability", ".tmp");