samples/bpf trace_output_user: Remove duplicate sys/ioctl.h include

Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Joe Stringer <joe@ovn.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-3awp0nv8tpnblatojmwjww7z@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

samples/bpf/trace_output_user.c

@@ -9,7 +9,6 @@
 #include <string.h>
 #include <fcntl.h>
 #include <poll.h>
-#include <sys/ioctl.h>
 #include <linux/perf_event.h>
 #include <linux/bpf.h>
 #include <errno.h>