hammer2 - Improve verbosity of CHECK errors on the console

hammer2 - Improve verbosity of CHECK errors on the console

* Improve the verbosity of CHECK errors on the console.  Print
  the block-type in human-readable form, and attempt to trace
  it back to its governing inode and report the inode number
  the error is in.

* Also print the device path string associated with the mount
  so we know what block device the error occurred on.