Silence shadow warning

Don't shadow path variable in the block to silence var being shadowed warnings in tests of rubygems and possibly others.

For example on rubygems master:

```
/home/rohit/.rvm/gems/ruby-2.1.4@global/gems/executable-hooks-1.3.2/lib/executable-hooks/regenerate_binstubs_command.rb:58: warning: shadowing outer local variable - path
```