tools headers uapi: Sync linux/fcntl.h with the kernel sources

To get the changes in:

96b2b072ee62be8a ("exportfs: allow exporting non-decodeable file handles to userspace")

That don't add anything that is handled by existing hard coded tables or
table generation scripts.

This silences this perf build warning:

Warning: Kernel ABI header differences:
diff -u tools/include/uapi/linux/fcntl.h include/uapi/linux/fcntl.h

Cc: Adrian Hunter <[e-mail]>
Cc: Amir Goldstein <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: Jan Kara <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Link: https://lore.kernel.org/lkml/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/include/uapi/linux/fcntl.h

···
 
 #define AT_RECURSIVE		0x8000	/* Apply to the entire subtree */
 
+/* Flags for name_to_handle_at(2). We reuse AT_ flag space to save bits... */
+#define AT_HANDLE_FID		AT_REMOVEDIR	/* file handle is needed to
+					compare object identity and may not
+					be usable to open_by_handle_at(2) */
+
 #endif /* _UAPI_LINUX_FCNTL_H */