[PATCH] EDAC: edac_mc_add_mc fix [2/2]

This is part 2 of a 2-part patch set.

Fix edac_mc_add_mc() so it cleans up properly if call to
edac_create_sysfs_mci_device() fails.

Signed-off-by: David S. Peterson <dsp@llnl.gov>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>