tools/lib/lockdep: Fix the build on recent kernels

The following upstream commit:

  4a389810bc3c ("kernel/locking/lockdep.c: convert hash tables to hlists")

broke the tools/lib/lockdep build. Add trivial RCU wrappers to fix it.

These wrappers should probably be moved into their own header file.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Krinkin <krinkin.m.u@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/tools/lib/lockdep/lockdep.c b/tools/lib/lockdep/lockdep.c
index f42b7e9..a0a2e3a 100644
--- a/tools/lib/lockdep/lockdep.c
+++ b/tools/lib/lockdep/lockdep.c
@@ -1,2 +1,8 @@
 #include <linux/lockdep.h>
+
+/* Trivial API wrappers, we don't (yet) have RCU in user-space: */
+#define hlist_for_each_entry_rcu	hlist_for_each_entry
+#define hlist_add_head_rcu		hlist_add_head
+#define hlist_del_rcu			hlist_del
+
 #include "../../../kernel/locking/lockdep.c"