edac: Fix spelling errors.

Signed-off-by: David Mackey <tdmackey@twitter.com>
Signed-off-by: Vinson Lee <vlee@twitter.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>