nvme: fixup memory leak in nvme_init_identify()

If nvme_get_effects_log() failed the 'id' buffer from the previous
nvme_identify_ctrl() call will never be freed.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>