Use atomics in find_successor() like in find_predecessor()

Use atomics in find_successor() like in find_predecessor().

Ref: oneapi-src#1175

Signed-off-by: Lukasz Dorau <[email protected]>

Author: ldorau

src/critnib/critnib.c

@@ -645,7 +645,9 @@ static struct critnib_leaf *find_successor(struct critnib_node *__restrict n) {
     while (1) {
         unsigned nib;
         for (nib = 0; nib <= NIB; nib++) {
-            if (n->child[nib]) {
+            struct critnib_node *m;
+            utils_atomic_load_acquire_ptr((void **)&n->child[nib], (void **)&m);
+            if (m) {
                 break;
             }
         }
@@ -654,7 +656,7 @@ static struct critnib_leaf *find_successor(struct critnib_node *__restrict n) {
             return NULL;
         }
 
-        n = n->child[nib];
+        utils_atomic_load_acquire_ptr((void **)&n->child[nib], (void **)&n);
 
         if (!n) {
             return NULL;