watchdog: Use sysfs_emit() and sysfs_emit_at() in "show" functions

Convert sprintf() in sysfs "show" functions to sysfs_emit() and
sysfs_emit_at() in order to check for buffer overruns in sysfs outputs.

Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210511061812.480172-1-juergh@canonical.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>