Remove unused @cache_hit Hash assignment

In 2abf6ca0 @cache_hit got introduced.
This was renamed to @cache_hits and revised in the subsequent commit
8240636b but it seems one assignment was
overlooked.

actionview/lib/action_view/base.rb

@@ -267,7 +267,6 @@ def initialize(lookup_context = nil, assigns = {}, controller = nil, formats = N
       @view_renderer = ActionView::Renderer.new @lookup_context
       @current_template = nil
 
-      @cache_hit = {}
       assign(assigns)
       assign_controller(controller)
       _prepare_context