wdt_reset_cause(): Improved error handling
wdt_reset_cause(): Improved error handling

This patch clears the user reason for every call, this to handle the
corner case when /var/lib/watchdogd.state does not exist, i.e. at first
boot, or as long as there has been no problem.

Signed-off-by: Joachim Nilsson <583c295fd7602c168ad814279bbc3894ba65f5d6@gmail.com>

troglobit/watchdogd,troglobit/watchdogd