qemu: Fix setting global_period cputune element

When VIR_DOMAIN_SCHEDULER_GLOBAL_PERIOD is matched "cputune.global_period"
should be updated and not "cputune.period".
Signed-off-by: NKaterina Koukiou <kkoukiou@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1600427Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_driver.c

@@ -10556,7 +10556,7 @@ qemuDomainSetSchedulerParametersFlags(virDomainPtr dom,
             }
 
             if (persistentDef)
-                persistentDefCopy->cputune.period = value_ul;
+                persistentDefCopy->cputune.global_period = value_ul;
 
         } else if (STREQ(param->field, VIR_DOMAIN_SCHEDULER_GLOBAL_QUOTA)) {
             SCHED_RANGE_CHECK(value_l, VIR_DOMAIN_SCHEDULER_GLOBAL_QUOTA,