Driver core: fix error by cleanup up symlinks properly

When a device fails to register the class symlinks where not cleaned up.
This left a symlink in the /sys/class/"device"/ directory that pointed
to no where. This caused the sysfs_follow_link Oops I reported earlier.
This patch cleanups up the symlink. Please apply. Thank you.

Signed-Off: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>