bluestore/bluestore_types: avoid heap-buffer-overflow in another way to keep code uniformity

Signed-off-by: Rongqi Sun <[email protected]>

Author: Svelar

src/os/bluestore/bluestore_types.h

@@ -1377,12 +1377,12 @@ struct sb_info_space_efficient_map_t {
       if (aux_items.size() != 0) {
 	auto it = std::lower_bound(
 	  aux_items.begin(),
-	  aux_items.end(),
+	  aux_items.end() - 1,
 	  id,
 	  [](const sb_info_t& a, const uint64_t& b) {
 	    return a < b;
 	  });
-        if (it != aux_items.end() && it->get_sbid() == id) {
+        if (it->get_sbid() == id) {
 	  return it;
 	}
       }