debian: Use DODTIME instead of DIETIME in init scripts

debian: Use DODTIME instead of DIETIME in init scripts

Brad pointed out that openvswitch-ipsec init script defined the variable
DIETIME but attempted to use it as DODTIME.  This commit uses DODTIME,
since it's the name used by the openvswitch-switch init script.  The
openvswitch-controller init script had the same issue.

As suggested by Ben, the "s" suffixes are removed from sleep commands,
since they are a GNU extension.

Reported-by: Brad Hall <brad@nicira.com>