udp: Remove duplicate included header file trace/events/udp.h

Remove duplicate included header file trace/events/udp.h and the
following warning reported by make includecheck:

  trace/events/udp.h is included more than once

Compile-tested only.
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240706071132.274352-2-thorsten.blum@toblux.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

net/ipv6/udp.c

@@ -46,7 +46,6 @@
 #include <net/tcp_states.h>
 #include <net/ip6_checksum.h>
 #include <net/ip6_tunnel.h>
-#include <trace/events/udp.h>
 #include <net/xfrm.h>
 #include <net/inet_hashtables.h>
 #include <net/inet6_hashtables.h>