[PATCH] libata: kill illegal kfree(id)

Kill kfree(id) in failure path of ata_dev_read_id().  id is not
dynamically allocated yet.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>