tools include UAPI: Update linux/mount.h copy

To pick the changes from:

dd8b477f9a3d8edb ("mount: Support "nosymfollow" in new mount api")

That ends up adding support for the new MOUNT_ATTR_NOSYMFOLLOW mount
attribute:

$ tools/perf/trace/beauty/fsmount.sh > before
$ cp include/uapi/linux/mount.h tools/include/uapi/linux/mount.h
$ tools/perf/trace/beauty/fsmount.sh > after
$ diff -u before after
--- before 2021-07-01 13:34:04.542517355 -0300
+++ after 2021-07-01 13:34:12.423694537 -0300
@@ -7,4 +7,5 @@
[ilog2(0x00000020) + 1] = "STRICTATIME",
[ilog2(0x00000080) + 1] = "NODIRATIME",
[ilog2(0x00100000) + 1] = "IDMAP",
+ [ilog2(0x00200000) + 1] = "NOSYMFOLLOW",
};
$

So now one can use it in --filter expressions for tracepoints.

This silences this perf build warnings:

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

Cc: Christian Brauner <[e-mail]>
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/include/uapi/linux/mount.h

···
 #define MOUNT_ATTR_STRICTATIME	0x00000020 /* - Always perform atime updates */
 #define MOUNT_ATTR_NODIRATIME	0x00000080 /* Do not update directory access times */
 #define MOUNT_ATTR_IDMAP	0x00100000 /* Idmap mount to @userns_fd in struct mount_attr. */
+#define MOUNT_ATTR_NOSYMFOLLOW	0x00200000 /* Do not follow symlinks */
 
 /*
  * mount_setattr()