Use lamont's magic error handling

Tiny tweak to grab the first item so we actually get the hash back in the error handling.

Given:

```ruby
package %w{curl totally_junk_pkg} do
  action :upgrade
end
```

```
    * No candidate version available for totally_junk_pkg
    ================================================================================
    Error executing action `upgrade` on resource 'homebrew_package[curl, totally_junk_pkg]'
    ================================================================================

    Chef::Exceptions::Package
    -------------------------
    No candidate version available for totally_junk_pkg
```

Signed-off-by: Tim Smith <tsmith@chef.io>

1 files changed, 3 insertions, 2 deletions

diff --git a/spec/unit/provider/package/homebrew_spec.rb b/spec/unit/provider/package/homebrew_spec.rb
index 62d8aee6f1..9975e72b02 100644
--- a/spec/unit/provider/package/homebrew_spec.rb
+++ b/spec/unit/provider/package/homebrew_spec.rb
@@ -238,9 +238,10 @@ describe Chef::Provider::Package::Homebrew do
       expect(provider.brew_info).to have_key("vim")
     end
 
-    it "returns empty hash if brew_cmd_output_data returned empty stdout" do
+    it "returns empty hash for packages if they lack data" do
+      new_resource.package_name %w{bogus}
       allow(provider).to receive(:brew_cmd_output).and_return("")
-      expect(provider.brew_info).to eq({})
+      expect(provider.brew_info).to eq("bogus" => {})
     end
   end