cxgbe(4): Always display an error message if SIOCSIFFLAGS will leave
IFF_UP and IFF_DRV_RUNNING out of sync. ifhwioctl in the kernel pays no
attention to the return code from the driver ioctl during SIOCSIFFLAGS
so these messages are the only indication that the ioctl was called but
failed.

MFC after: 1 week
Sponsored by: Chelsio Communications