nvme-multipath: zero out ANA log buffer

When nvme_init_identify() fails the ANA log buffer is deallocated
but _not_ set to NULL. This can cause double free oops when this
controller is deleted without ever being reconnected.
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/multipath.c

@@ -570,6 +570,7 @@ int nvme_mpath_init(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 	return 0;
 out_free_ana_log_buf:
 	kfree(ctrl->ana_log_buf);
+	ctrl->ana_log_buf = NULL;
 out:
 	return error;
 }
@@ -577,5 +578,6 @@ int nvme_mpath_init(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
 {
 	kfree(ctrl->ana_log_buf);
+	ctrl->ana_log_buf = NULL;
 }