call virstateCleanup to do the cleanup before libvirtd exits

https://bugzilla.redhat.com/show_bug.cgi?id=903184

(cherry picked from commit 47e17677)

daemon/libvirtd.c

@@ -1371,5 +1371,7 @@ cleanup:
 
     daemonConfigFree(config);
 
+    virStateCleanup();
+
     return ret;
 }