Fix inline comments for assumed_tracked (#4762)

Summary:
Fix the definition of assumed_tracked in Transaction that was introduced in #4680
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4762

Differential Revision: D13399150

Pulled By: maysamyabandeh

fbshipit-source-id: 2a30fe49e3c44adacd7e45cd48eae95023ca9dca

include/rocksdb/utilities/transaction.h

@@ -293,7 +293,7 @@ class Transaction {
   // functions in WriteBatch, but will also do conflict checking on the
   // keys being written.
   //
-  // assume_tracked=false expects the key be already tracked. If valid then it
+  // assume_tracked=true expects the key be already tracked. If valid then it
   // skips ValidateSnapshot. Returns error otherwise.
   //
   // If this Transaction was created on an OptimisticTransactionDB, these