qemuDomainSetLifecycleAction: Add a note about argument range-check

The public API wrapper range-checks the arguments. Save the next reader
the hassle of looking it up.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_driver.c

@@ -19652,6 +19652,8 @@ qemuDomainSetLifecycleAction(virDomainPtr dom,
     virDomainDef *persistentDef = NULL;
     int ret = -1;
 
+    /* note that 'action' and 'type' are range-checked in the public API wrapper */
+
     virCheckFlags(VIR_DOMAIN_AFFECT_LIVE |
                   VIR_DOMAIN_AFFECT_CONFIG, -1);