ipv4: coding style: comparison for inequality with NULL

The ipv4 code uses a mixture of coding styles. In some instances check
for non-NULL pointer is done as x != NULL and sometimes as x. x is
preferred according to checkpatch and this patch makes the code
consistent by adopting the latter form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/ipv4/af_inet.c
Simple merge

diff --cc net/ipv4/arp.c
Simple merge

diff --cc net/ipv4/cipso_ipv4.c
Simple merge

diff --cc net/ipv4/devinet.c
Simple merge

diff --cc net/ipv4/fib_trie.c
Simple merge

diff --cc net/ipv4/geneve.c
Simple merge

diff --cc net/ipv4/gre_offload.c
Simple merge

diff --cc net/ipv4/igmp.c
Simple merge

diff --cc net/ipv4/inet_connection_sock.c
Simple merge

diff --cc net/ipv4/inet_hashtables.c
Simple merge

diff --cc net/ipv4/inet_timewait_sock.c
Simple merge

diff --cc net/ipv4/ip_fragment.c
Simple merge

diff --cc net/ipv4/ip_input.c
Simple merge

diff --cc net/ipv4/ip_options.c
Simple merge

diff --cc net/ipv4/ip_output.c
Simple merge

diff --cc net/ipv4/ip_sockglue.c
Simple merge

diff --cc net/ipv4/ip_tunnel.c
Simple merge

diff --cc net/ipv4/ip_vti.c
Simple merge

diff --cc net/ipv4/ipmr.c
Simple merge

diff --cc net/ipv4/ping.c
Simple merge

diff --cc net/ipv4/raw.c
Simple merge

diff --cc net/ipv4/route.c
Simple merge

diff --cc net/ipv4/tcp.c
Simple merge

diff --cc net/ipv4/tcp_diag.c
Simple merge

diff --cc net/ipv4/tcp_input.c
Simple merge

diff --cc net/ipv4/tcp_ipv4.c
Simple merge

diff --cc net/ipv4/tcp_minisocks.c
Simple merge

diff --cc net/ipv4/tcp_output.c
Simple merge

diff --cc net/ipv4/udp.c
Simple merge

diff --cc net/ipv4/udp_offload.c
Simple merge