ipv4, ping: Remove duplicate icmp.h include

Remove the duplicate inclusion of net/icmp.h from net/ipv4/ping.c
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ping.c

@@ -41,7 +41,6 @@
 #include <linux/proc_fs.h>
 #include <net/sock.h>
 #include <net/ping.h>
-#include <net/icmp.h>
 #include <net/udp.h>
 #include <net/route.h>
 #include <net/inet_common.h>