nvme: convert sysfs sprintf/snprintf family to sysfs_emit
Fix the following coccicheck warning:
./drivers/nvme/host/core.c:3580:8-16: WARNING: use scnprintf or sprintf.
./drivers/nvme/host/core.c:3570:8-16: WARNING: use scnprintf or sprintf.
./drivers/nvme/host/core.c:3560:8-16: WARNING: use scnprintf or sprintf.
./drivers/nvme/host/core.c:3526:8-16: WARNING: use scnprintf or sprintf.
./drivers/nvme/host/core.c:2833:8-16: WARNING: use scnprintf or sprintf.