tools/liblockdep: add userspace versions of WRITE_ONCE and RCU_INIT_POINTER

These were added to the kernel code in cee34d88 ("lockdep: Fix a race between
/proc/lock_stat and module unload"). There's nothing special we need to do
about them in userspace.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

tools/lib/lockdep/uinclude/linux/compiler.h

@@ -3,5 +3,7 @@
 
 #define __used		__attribute__((__unused__))
 #define unlikely
+#define WRITE_ONCE(x, val) x=(val)
+#define RCU_INIT_POINTER(p, v) p=(v)
 
 #endif