net: dsa: sja1105: flower: reject cross-chip redirect

In the Linux kernel, the following vulnerability has been resolved: net: dsa: sja1105: flower: reject cross-chip redirect dsa_port_from_netdev() may return a valid port from a different switch chip. Programming another chip's port index into the local hardware causes redirection to the wrong port, or an out-of-bounds access if the index exceeds the local chip's port count. Apply a minimal fix that adds a check to catch this case and adjusts the extack message. When cls->common.skip_sw is not set, the operation could instead redirect to the upstream port and let the software or upstream switch(es) handle the forward, but that is not addressed here.