nvme: fix typo in status code constant for self-test in progress

Correct a typo error in the NVMe status code constant from
NVME_SC_SELT_TEST_IN_PROGRESS to NVME_SC_SELF_TEST_IN_PROGRESS to
accurately reflect its meaning.

Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>