drivers/edac: fix leaf sysfs attribute

This patch fixes and enhances the driver level set of sysfs attributes that
can be added to the 'block' level of an edac_device type of driver.

There is a controller information structure, which contains one or more
instances of device.  Each instance will have one or more blocks of device
specific counters.  This patch fixes the ability to have more detailed
attributes/controls for each of the 'blocks', providing for the addition of
controls/attributes from the low level driver to user space via sysfs.

Cc: Alan Cox alan@lxorguk.ukuu.org.uk
Signed-off-by: Douglas Thompson <dougthompson@xmission.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>