Always close the last report output stream

Should fix #701

src/global.h

@@ -56,6 +56,11 @@ public:
   global_scope_t(char ** envp);
   ~global_scope_t();
 
+  void quick_close() {
+    if (! report_stack.empty())
+      report_stack.front().quick_close();
+  }
+
   virtual string description() {
     return _("global scope");
   }

src/main.cc

@@ -212,6 +212,7 @@ int main(int argc, char * argv[], char * envp[])
   } else
 #endif
   {
+    global_scope->quick_close();
     INFO("Ledger ended");       // let global_scope leak!
   }
 

src/report.h

@@ -125,6 +125,10 @@ public:
     output_stream.close();
   }
 
+  void quick_close() {
+    output_stream.close();
+  }
+
   virtual string description() {
     return _("current report");
   }