[PATCH] nvme: free sq/cq dbbuf pointers when dbbuf set fails

[Keith Busch]

On Thu, Nov 05, 2020 at 11:28:47PM +0900, Minwoo Im wrote:
> If Doorbell Buffer Config command fails even 'dev->dbbuf_dbs != NULL'
> which means OACS indicates that NVME_CTRL_OACS_DBBUF_SUPP is set,
> nvme_dbbuf_update_and_check_event() will check event even it's not been
> successfully set.
> 
> This patch fixes mismatch among dbbuf for sq/cqs in case that dbbuf
> command fails.

This fixes if host dbbuf was successfully configured at one point, but
fails on a subsequent reset, correct? Otherwise, I don't see how the
queue's dbbuf values would have been set to non-NULL.