Remove unused variable

c/lib/hashmap.h

@@ -42,7 +42,6 @@ void aoc_hashmap_put(AocHashmap *map, char *key, void *value) {
     node->value = value;
     node->next = NULL;
   } else {
-    AocHashmapNode *next = node->next;
     while (node->next != NULL) {
       node = node->next;
     }