qemu: Simplify condition with already extracted flag

src/qemu/qemu_driver.c

@@ -12354,7 +12354,7 @@ static int qemuDomainSnapshotDelete(virDomainSnapshotPtr snapshot,
     if (!(snap = qemuSnapObjFromSnapshot(vm, snapshot)))
         goto cleanup;
 
-    if (!(flags & VIR_DOMAIN_SNAPSHOT_DELETE_METADATA_ONLY)) {
+    if (!metadata_only) {
         if (!(flags & VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN_ONLY) &&
             virDomainSnapshotIsExternal(snap))
             external++;