Fix comment spelling (#7960)

Summary:
terated -> treated

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7960

Reviewed By: ajkr

Differential Revision: D26677005

Pulled By: zhichao-cao

fbshipit-source-id: 6221305afb263aa60f674a4113aa30cb8f3914e6

include/rocksdb/memtablerep.h

@@ -62,7 +62,7 @@ class MemTableRep {
     typedef ROCKSDB_NAMESPACE::Slice DecodedType;
 
     virtual DecodedType decode_key(const char* key) const {
-      // The format of key is frozen and can be terated as a part of the API
+      // The format of key is frozen and can be treated as a part of the API
       // contract. Refer to MemTable::Add for details.
       return GetLengthPrefixedSlice(key);
     }