net/: Run nxstyle against all C files.

net/ipforward/ipv4_forward.c

@@ -163,6 +163,7 @@ static int ipv4_decr_ttl(FAR struct ipv4_hdr_s *ipv4)
     {
 #ifdef CONFIG_NET_ICMP
       /* Return an ICMP error packet back to the sender. */
+
 #  warning Missing logic
 #endif
 
@@ -488,6 +489,7 @@ int ipv4_forward(FAR struct net_driver_s *dev, FAR struct ipv4_hdr_s *ipv4)
        */
 
       /* Correct dev->d_buf by adding back the L1 header length */
+
 #endif
 
       nwarn("WARNING: Packet forwarding to same device not supportedN\n");

net/ipforward/ipv6_forward.c

@@ -159,6 +159,7 @@ static int ipv6_decr_ttl(FAR struct ipv6_hdr_s *ipv6)
     {
 #ifdef CONFIG_NET_ICMPv6
       /* Return an ICMPv6 error packet back to the sender. */
+
 #  warning Missing logic
 #endif
 
@@ -635,6 +636,7 @@ int ipv6_forward(FAR struct net_driver_s *dev, FAR struct ipv6_hdr_s *ipv6)
            */
 
           /* Correct dev->d_buf by adding back the L1 header length */
+
 #endif
 
           /* Nothing other 6LoWPAN forwarding is currently handled and that