docs: futex: Fix kernel-doc references

Since the futex code was restructured, there's no futex.c file anymore
and the implementation is split in various files. Point kernel-doc
references to the new files.
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211012135549.14451-1-andrealmeid@collabora.com

Documentation/kernel-hacking/locking.rst

@@ -1352,7 +1352,19 @@ Mutex API reference
 Futex API reference
 ===================
 
-.. kernel-doc:: kernel/futex.c
+.. kernel-doc:: kernel/futex/core.c
+   :internal:
+
+.. kernel-doc:: kernel/futex/futex.h
+   :internal:
+
+.. kernel-doc:: kernel/futex/pi.c
+   :internal:
+
+.. kernel-doc:: kernel/futex/requeue.c
+   :internal:
+
+.. kernel-doc:: kernel/futex/waitwake.c
    :internal:
 
 Further reading

Documentation/translations/it_IT/kernel-hacking/locking.rst

@@ -1396,7 +1396,19 @@ Riferimento per l'API dei Mutex
 Riferimento per l'API dei Futex
 ===============================
 
-.. kernel-doc:: kernel/futex.c
+.. kernel-doc:: kernel/futex/core.c
+   :internal:
+
+.. kernel-doc:: kernel/futex/futex.h
+   :internal:
+
+.. kernel-doc:: kernel/futex/pi.c
+   :internal:
+
+.. kernel-doc:: kernel/futex/requeue.c
+   :internal:
+
+.. kernel-doc:: kernel/futex/waitwake.c
    :internal:
 
 Approfondimenti