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

To pick the changes from:

  b383a73f ("fs/ext4: Introduce DAX inode flag")

And silence 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

It causes various beautifiers for things like fspick, fsmount, etc (see
below) to get rebuilt, but this specific change doesn't make 'perf
trace' be capable of decoding anything new, as we still don't decode
what comes from ioctls, just its cmds.

Details about the update:

  $ cp include/uapi/linux/fs.h tools/include/uapi/linux/fs.h
  $ git diff
  diff --git a/tools/include/uapi/linux/fs.h b/tools/include/uapi/linux/fs.h
  index 379a612f8f1d..f44eb0a04afd 100644
  --- a/tools/include/uapi/linux/fs.h
  +++ b/tools/include/uapi/linux/fs.h
  @@ -262,6 +262,7 @@ struct fsxattr {
   #define FS_EA_INODE_FL                 0x00200000 /* Inode used for large EA */
   #define FS_EOFBLOCKS_FL                        0x00400000 /* Reserved for ext4 */
   #define FS_NOCOW_FL                    0x00800000 /* Do not cow file */
  +#define FS_DAX_FL                      0x02000000 /* Inode is DAX */
   #define FS_INLINE_DATA_FL              0x10000000 /* Reserved for ext4 */
   #define FS_PROJINHERIT_FL              0x20000000 /* Create with parents projid */
   #define FS_CASEFOLD_FL                 0x40000000 /* Folder is case insensitive */
  $ m
  make: Entering directory '/home/acme/git/perf/tools/perf'
    BUILD:   Doing 'make -j8' parallel build
    INSTALL  GTK UI
    CC       /tmp/build/perf/builtin-trace.o
    DESCEND  plugins
    CC       /tmp/build/perf/trace/beauty/fsmount.o
    CC       /tmp/build/perf/trace/beauty/fspick.o
    CC       /tmp/build/perf/trace/beauty/mount_flags.o
    CC       /tmp/build/perf/trace/beauty/move_mount.o
    CC       /tmp/build/perf/trace/beauty/renameat.o
    CC       /tmp/build/perf/trace/beauty/sync_file_range.o
    INSTALL  trace_plugins
    LD       /tmp/build/perf/trace/beauty/perf-in.o
    LD       /tmp/build/perf/perf-in.o
    LINK     /tmp/build/perf/perf
  <SNIP>

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/include/uapi/linux/fs.h

@@ -262,6 +262,7 @@ struct fsxattr {
 #define FS_EA_INODE_FL			0x00200000 /* Inode used for large EA */
 #define FS_EOFBLOCKS_FL			0x00400000 /* Reserved for ext4 */
 #define FS_NOCOW_FL			0x00800000 /* Do not cow file */
+#define FS_DAX_FL			0x02000000 /* Inode is DAX */
 #define FS_INLINE_DATA_FL		0x10000000 /* Reserved for ext4 */
 #define FS_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
 #define FS_CASEFOLD_FL			0x40000000 /* Folder is case insensitive */