shell/Windows: Fix the view not being updated on StateError

shell/Windows: Fix the view not being updated on StateError

Since StateError == 0, if this was the status used when the path
isn't in the map already, the view would not be updated since the
new state would be the same as the default-constructed state in the
map. Fix by explicitly inserting in that case, this also avoid aving
to do two lookups in the map when a path already has an entry.