Fix a typo (bug) when setting error during Flush (#6928)

Summary:
As title. The prior change to the line is a typo. Fixing it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6928

Test Plan: make check

Reviewed By: zhichao-cao

Differential Revision: D21873587

Pulled By: riversand963

fbshipit-source-id: f4837fc8792d7106bc230b7b499dfbb7a2847430

db/db_impl/db_impl_compaction_flush.cc

@@ -573,7 +573,7 @@ Status DBImpl::AtomicFlushMemTablesToOutputFiles(
   // Need to undo atomic flush if something went wrong, i.e. s is not OK and
   // it is not because of CF drop.
   if (!s.ok() && !s.IsColumnFamilyDropped()) {
-    if (!io_s.ok() && io_s.IsColumnFamilyDropped()) {
+    if (!io_s.ok() && !io_s.IsColumnFamilyDropped()) {
       error_handler_.SetBGError(io_s, BackgroundErrorReason::kFlush);
     } else {
       Status new_bg_error = s;