Edited lvm_volume_group(:extend) and lvm_logical_volume(:resize) issues

`lvm_volume_group` would create logical volumes correctly.  When the `extend` options were added there was no way for an internal `logical_volume` resource to resize.  It will now execute the `:resize` action on logical volumes when the logical volume group is extended.

Example code:
```ruby
lvm_volume_group 'test' do
  physical_volumes ['/dev/vdc', '/dev/vdd']
  action [:create, :extend]

  logical_volume 'main' do
    size '100%FREE'
    filesystem 'ext4'
    mount_point '/srv'
    take_up_free_space true
  end
end
```

There was also an issue with the `:resize` action where `lv.path` didn't exist and would fail during run.  I changed `lv.path` to `device_name` which is they way it is used in the `:create` resource.