Move in_aton to allow netpoll and pktgen to work without the rest of
the IPv4 stack. Fix whitespace and add comment for the odd placement.

Delete now-empty net/ipv4/utils.c

Re-enable netpoll/netconsole without CONFIG_INET
Signed-off-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>