CAM: Keep periph_links when restoring CCB in camperiphdone().
While recovery command executed, some other commands from the periph may complete, that may affect periph_links of this CCB. So restoring original CCB we must keep current periph_links as more up to date. I've found this triggering assertions with debug kernel and suspect some memory corruptions otherwise when spun down disk receives two or sometimes more concurrent requests. MFC after: 1 week Sponsored by: iXsystems, Inc.