[cleanup] While reading the code.

Fix comment typo in story_storage.cc

TEST=none

Change-Id: Ie98980356aee95a9f0fbcb08053308598a34e017
diff --git a/bin/sessionmgr/storage/story_storage.cc b/bin/sessionmgr/storage/story_storage.cc
index 42acc05..07581ad 100644
--- a/bin/sessionmgr/storage/story_storage.cc
+++ b/bin/sessionmgr/storage/story_storage.cc
@@ -829,7 +829,7 @@
 
 void StoryStorage::OnPageConflict(Conflict* conflict) {
   // TODO(thatguy): Add basic conflict resolution. We can force a conflict for
-  // link data in tests by using Page.StartTranscation() in UpdateLinkValue().
+  // link data in tests by using Page.StartTransaction() in UpdateLinkValue().
   FXL_LOG(WARNING) << "StoryStorage::OnPageConflict() for link key "
                    << to_string(conflict->key);
 }