show() should not use snprintf() when formatting the value to be
returned to user space.

Fix the following coccicheck warning:
drivers/media/i2c/ccs/ccs-core.c:3761: WARNING: use scnprintf or sprintf.
Signed-off-by: Qing Wang <wangqing@vivo.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>