Fix typo in example

example/comp_doc_anonymous_semaphoreB.cpp

@@ -29,7 +29,7 @@ int main ()
 
    //Create a shared memory object.
    shared_memory_object shm
-      (open_only                    //only create
+      (open_only                    //only open
       ,"MySharedMemory"              //name
       ,read_write  //read-write mode
       );