CONFIG_HOTPLUG is always enabled now, so remove the unused code that was
trying to be compiled out when this option was disabled, in the
networking core.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>