crimson/os/seastore/btree: remove unused methods

Signed-off-by: Xuehan Xu <[email protected]>

Author: xxhdx1985126

src/crimson/os/seastore/btree/fixed_kv_btree.h

@@ -312,17 +312,6 @@ class FixedKVBtree {
       }
       return get_depth();
     }
-
-    depth_t check_merge() const {
-      if (!leaf.node->below_min_capacity()) {
-	return 0;
-      }
-      for (depth_t merge_from = 1; merge_from < get_depth(); ++merge_from) {
-	if (!get_internal(merge_from + 1).node->below_min_capacity())
-	  return merge_from;
-      }
-      return get_depth();
-    }
   };
 
   FixedKVBtree(RootBlockRef &root_block) : root_block(root_block) {}