cpufreq: ondemand: Simplify conditionals in od_dbs_timer()

Reduce the indentation level in the conditionals in od_dbs_timer()
and drop the delay variable from it.

No functional changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>