Remove flag checking in MacVLanCreate helper stub

When compiling without WITH_MACVTAP, we can get:
'unsupported flags (0x1) in function
virNetDevMacVLanCreateWithVPortProfile'
on an attempt to start a domain.

Remove the flag check to reach the more helpful error:
Cannot create macvlan devices on this platform

https://bugzilla.redhat.com/show_bug.cgi?id=1186928

src/util/virnetdevmacvlan.c

@@ -1066,9 +1066,8 @@ int virNetDevMacVLanCreateWithVPortProfile(const char *ifname ATTRIBUTE_UNUSED,
                                            char **res_ifname ATTRIBUTE_UNUSED,
                                            virNetDevVPortProfileOp vmop ATTRIBUTE_UNUSED,
                                            char *stateDir ATTRIBUTE_UNUSED,
-                                           unsigned int flags)
+                                           unsigned int flags ATTRIBUTE_UNUSED)
 {
-    virCheckFlags(0, -1);
     virReportSystemError(ENOSYS, "%s",
                          _("Cannot create macvlan devices on this platform"));
     return -1;