Add ethernet type check in ifsetlro()

[Jan Klemkow]

Hi,

bluhm pointed out that the ether_brport_isset() check it just allowed on
ethernet devices.  Thus, I put an additional ethernet check in the
condition.  This also fixes EBUSY errors of "ifconfig lo0 tcplro" calls
in my setup.

ok?

bye,
Jan

Index: net/if.c
===================================================================
RCS file: /cvs/src/sys/net/if.c,v
retrieving revision 1.702
diff -u -p -r1.702 if.c
--- net/if.c    2 Jul 2023 19:59:15 -0000       1.702
+++ net/if.c    3 Jul 2023 20:58:32 -0000
@@ -3206,7 +3206,7 @@ ifsetlro(struct ifnet *ifp, int on)
        KERNEL_ASSERT_LOCKED(); /* for if_flags */
 
        if (on && !ISSET(ifp->if_xflags, IFXF_LRO)) {
-               if (ether_brport_isset(ifp)) {
+               if (ifp->if_type == IFT_ETHER && ether_brport_isset(ifp)) {
                        error = EBUSY;
                        goto out;
                }