When d_make_root() fails it will automatically drop the reference
on the root inode.  We should not be doing so as well.
Signed-off-by: NAndy Whitcroft <apw@canonical.com>
Acked-by: NMatthew Garrett <mjg@redhat.com>
Acked-by: NJeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>