drivers/edac: device output clenaup

The error handling output strings needed to be refactored for better
displaying of the error informaton.

Also needed to added offset_value for output as well

Signed-off-by: Douglas Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>