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().

sprintf() and scnprintf() will be converted as well if they have.

Generally, this patch is generated by
make coccicheck M=<path/to/file> MODE=patch \
COCCI=scripts/coccinelle/api/device_attr_show.cocci

No functional change intended

CC: Jiri Kosina <jikos@kernel.org>
CC: Jonathan Cameron <jic23@kernel.org>
CC: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
CC: Benjamin Tissoires <benjamin.tissoires@redhat.com>
CC: linux-input@vger.kernel.org
CC: linux-iio@vger.kernel.org
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>