conf: remove outdated comment

When using the ENUM macros, the compiler guards that the declaration
and implementation are in sync.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Acked-by: NPeter Krempa <pkrempa@redhat.com>

src/conf/domain_conf.h

@@ -119,7 +119,6 @@ struct _virDomainDeviceDef {
 };
 
 /* Different types of hypervisor */
-/* NB: Keep in sync with virDomainVirtTypeToString impl */
 typedef enum {
     VIR_DOMAIN_VIRT_NONE = 0,
     VIR_DOMAIN_VIRT_QEMU,