rcheck: Supply a default list of hosts if none are given.

[rcheck] / check.d / logs

#! /bin/sh
###
### Report on scary things found in log files.

set -e

## Check Exim's paniclog to see whether it was upset about anything.
if [ -s /var/log/exim4/paniclog ]; then
  echo "W: Exim paniclog exists.  Be afraid."
fi