Consistently wrap access to queue heads/tails, so it's easier to make
further changes. Adjust sqhd_advance() to match the head/tail naming of
the accessor functions, and move the definitions to be close to each
other.
Signed-off-by: John Levon <john.levon@nutanix.com>
Change-Id: I197e230ecc4e67fe0207f29281d7e4ca946c22e1
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/11295
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>