Change status checks to align with the existing style and remove the
explicit check against NVME_SUCCESS.

Cc: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Gollu Appalanaidu <anaidu.gollu@samsung.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>