cpufreq: powernow-k8: Drop unnecessary return statements from two functions

The script "checkpatch.pl" pointed information out like the following.

WARNING: void function return statements are not generally useful

Thus remove such a statement in the affected functions.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/powernow-k8.c

@@ -122,14 +122,12 @@ static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
 static void count_off_irt(struct powernow_k8_data *data)
 {
 	udelay((1 << data->irt) * 10);
-	return;
 }
 
 /* the voltage stabilization time */
 static void count_off_vst(struct powernow_k8_data *data)
 {
 	udelay(data->vstable * VST_UNITS_20US);
-	return;
 }
 
 /* need to init the control msr to a safe value (for each cpu) */