fix windows which

Signed-off-by: Lamont Granquist <lamont@scriptkiddie.org>

spec/unit/mixin/which_spec.rb

@@ -29,19 +29,16 @@ def transport_connection
   let(:file_helper) { FileHelperMock.new }
 
   before do
-    old_env = ENV
-    ENV["Path"] = ENV["PATH"] = "/usr/bin"
+    Ohai::Mixin::ChefUtilsWiring::PathCache.instance.path_cache = "/usr/bin"
     allow(file_helper).to receive(:name).and_return("Fakeclass")
     logger = instance_double("Mixlib::Log::Child", trace: nil, debug: nil, warn: nil)
     allow(file_helper).to receive(:logger).and_return(logger)
     allow(File).to receive(:executable?).and_return(false)
-    ENV = old_env
   end
 
   describe "which" do
     it "returns the path to an executable that is in the path" do
       allow(File).to receive(:executable?).with("/usr/bin/skyhawk").and_return(true)
-      allow(File).to receive(:directory?).with("/usr/bin/skyhawk").and_return(false)
       expect(file_helper.which("skyhawk")).to eql "/usr/bin/skyhawk"
     end