tools headers uapi: Update tools's copy of linux/vhost.h

tools headers uapi: Update tools's copy of linux/vhost.h

To get the changes in:

	c48300c92ad9 ("vhost: fix VHOST_GET_BACKEND_FEATURES ioctl request definition")

This makes 'perf trace' and other tools in the future using its
beautifiers in a libbeauty.so library be able to translate these new
ioctl to strings:

  $ tools/perf/trace/beauty/vhost_virtio_ioctl.sh  > /tmp/after
  $ diff -u /tmp/before /tmp/after
  --- /tmp/before	2018-09-11 13:10:57.923038244 -0300
  +++ /tmp/after	2018-09-11 13:11:20.329012685 -0300
  @@ -15,6 +15,7 @@
        [0x22] = "SET_VRING_ERR",
        [0x23] = "SET_VRING_BUSYLOOP_TIMEOUT",
        [0x24] = "GET_VRING_BUSYLOOP_TIMEOUT",
  +     [0x25] = "SET_BACKEND_FEATURES",
        [0x30] = "NET_SET_BACKEND",
        [0x40] = "SCSI_SET_ENDPOINT",
        [0x41] = "SCSI_CLEAR_ENDPOINT",
  @@ -27,4 +28,5 @@
   static const char *vhost_virtio_ioctl_read_cmds[] = {
        [0x00] = "GET_FEATURES",
        [0x12] = "GET_VRING_BASE",
  +	[0x26] = "GET_BACKEND_FEATURES",
  };
  $

We'll also use this to be able to express syscall filters using symbolic
these symbolic names, something like:

	# perf trace --all-cpus -e ioctl(cmd=*GET_FEATURES)

This silences the following warning during perf's build:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/vhost.h' differs from latest version at 'include/uapi/linux/vhost.h'
  diff -u tools/include/uapi/linux/vhost.h include/uapi/linux/vhost.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-35x71oei2hdui9u0tarpimbq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>