cnvt to staged_path in vmware-fusion6

Casks/vmware-fusion6.rb

@@ -10,6 +10,6 @@ class VmwareFusion6 < Cask
   app 'VMware Fusion.app'
   uninstall_preflight do
     system '/usr/bin/sudo', '-E', '--',
-           '/usr/sbin/chown', '-R', '--', "#{Etc.getpwuid(Process.euid).name}:staff", "#{destination_path}/VMware Fusion.app"
+           '/usr/sbin/chown', '-R', '--', "#{Etc.getpwuid(Process.euid).name}:staff", "#{staged_path}/VMware Fusion.app"
   end
 end