Fix Rx/Tx checksum offload ioctl handling. Now checksum offload can be controlled by ifconfig(8). Note, VLAN hardware tagging controls still lacks required handler but it requires more driver cleanups so I didn't touch that part.
Fix Rx/Tx checksum offload ioctl handling. Now checksum offload
can be controlled by ifconfig(8). Note, VLAN hardware tagging
controls still lacks required handler but it requires more driver
cleanups so I didn't touch that part.

PR:	kern/128766

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase