Fix computing ptr and update pool_size

Fix computing ptr and update pool_size
after freeing most of the first pool.
The first (main) pool has just been freed except of the first page
containing the metadata. The pool size has to be updated
and set to the size of one page.

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

Author: ldorau

src/base_alloc/base_alloc_linear.c

@@ -199,9 +199,11 @@ int umf_ba_linear_free(umf_ba_linear_pool_t *pool, void *ptr) {
         if ((pool->metadata.pool_n_allocs == 0) && pool->next_pool &&
             (pool->metadata.pool_size > page_size)) {
             // we can free the first (main) pool except of the first page containing the metadata
-            void *ptr = pool + page_size;
+            void *ptr = (char *)pool + page_size;
             size_t size = pool->metadata.pool_size - page_size;
             ba_os_free(ptr, size);
+            // update pool_size
+            pool->metadata.pool_size = page_size;
         }
         DEBUG_RUN_CHECKS(pool);
         util_mutex_unlock(&pool->metadata.lock);