Per filesystems/sysfs.rst, show() should only use sysfs_emit()
or sysfs_emit_at() when formatting the value to be returned to user space.

coccinelle complains that there are still a couple of functions that use
snprintf(). Convert them to sysfs_emit().

> ./drivers/platform/mellanox/mlxbf-bootctl.c:466:8-16: WARNING: please use sysfs_emit
> ./drivers/platform/mellanox/mlxbf-bootctl.c:584:8-16: WARNING: please use sysfs_emit
> ./drivers/platform/mellanox/mlxbf-bootctl.c:635:8-16: WARNING: please use sysfs_emit
> ./drivers/platform/mellanox/mlxbf-bootctl.c:686:8-16: WARNING: please use sysfs_emit
> ./drivers/platform/mellanox/mlxbf-bootctl.c:737:8-16: WARNING: please use sysfs_emit
> ./drivers/platform/mellanox/mlxbf-bootctl.c:788:8-16: WARNING: please use sysfs_emit
> ./drivers/platform/mellanox/mlxbf-bootctl.c:839:8-16: WARNING: please use sysfs_emit

No functional change intended
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Link: https://lore.kernel.org/r/20240116045151.3940401-12-lizhijian@fujitsu.comReviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>