TestGetfsstat is failing on OS X 10.8.

Not sure why. Add more debug info.

Change-Id: I7dabb70dd7aeffda7e8959103db9e4886b84741e
Reviewed-on: https://go-review.googlesource.com/28220Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>