nvme: rename nvme_sc_to_pr_err to nvme_status_to_pr_err

This should better match its semantic.  "sc" is used in the NVMe spec to
specifically refer to the last 8 bits in the status field. We should not
reuse "sc" here.

Signed-off-by: Weiwen Hu <huweiwen@linux.alibaba.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>