tools include uapi: Sync linux/fs.h copy with the kernel sources

To get the changes in:

  e262e32d

 ("vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled")

That made the mount flags string table generator to switch to using
mount.h instead.

This silences the following 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: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-mosz81pa6iwxko4p2owbm3ss@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>