some spelling mistake

bin/pt-duplicate-key-checker

@@ -5583,7 +5583,7 @@ optimizer, execute ALTER INDEX .. VISIBLE
 
 While dropping an index is a fast, background operation, adding indexes is
 a slow, CPU, and disk IO intensive operation. If you discover that an index
-was incorrectly dropped, it becomes a NOOP to make the index visable again,
+was incorrectly dropped, it becomes a NOOP to make the index visible again,
 compared to completely re-adding the index.
 
 =item --key-types

bin/pt-online-schema-change

@@ -8879,7 +8879,7 @@ sub main {
       # it's a hack, like ignoring a problem instead of fixing it somehow. We
       # should take a look at the things that get printed in a "normal"
       # non-quiet run, and "if !quiet" them, and then do some kind of Logger.pm
-      # or Messager.pm module for a future release.
+      # or Message.pm module for a future release.
       close STDOUT;
       open  STDOUT, '>', '/dev/null'
          or warn "Cannot reopen STDOUT to /dev/null: $OS_ERROR";