[PATCH] edac_mc: fix error handling

Call sysdev_class_unregister() on failure in edac_sysfs_memctrl_setup()
and decrease identation level for clear logic.

Acked-by: Doug Thompson <norsk5@xmission.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>