[Pacemaker] Bug in "ping" pacemaker resource agent

[Maros Timko]

Unfortunately, this is not the only bug of this RA.
1. There is absolute mess regarding the status file - some part of
code uses OCF_RESKEY_pidfile, some uses $OCF_RESKEY_state. It means
that the status handling does not work and you will end up with
following failure:
Jan 28 16:45:08 vsp7 lrmd: [17862]: info: RA output:
(ping:0:stop:stderr) rm: missing operand Try `rm --help' for more
information.

2. In validate-all there is also check $OCF_RESKEY_interval that has
no source, I am not sure if this should be dampen parameter or
$OCF_RESKEY_CRM_meta_interval.

I will try to fix that because it seems to be very interesting RA for
production.

Tino