tools headers UAPI: Sync linux/fs.h with the kernel sources

To pick the trivial change in:

  63c8af56 ("block: uapi: fix comment about block device ioctl")

This silences this perf build warning:

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

Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>