v3dv: duplicate key on hashtable insert

The key is created on stack, so as soon as the function returns this key
is lost, so the inserted key in the hashtable is invalid.

Rather, insert a duplicated version on heap.

This fixes a stack-buffer-overflow when running some Vulkan CTS tests.

Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16083>

src/broadcom/vulkan/v3dv_meta_copy.c

@@ -1885,7 +1885,7 @@ get_copy_texel_buffer_pipeline(
    mtx_lock(&device->meta.mtx);
    struct hash_entry *entry =
       _mesa_hash_table_search(device->meta.texel_buffer_copy.cache[image_type],
-                              &key);
+                              key);
    if (entry) {
       mtx_unlock(&device->meta.mtx);
       *pipeline = entry->data;
@@ -1914,8 +1914,10 @@ get_copy_texel_buffer_pipeline(
    if (!ok)
       goto fail;
 
+   uint8_t *dupkey = malloc(V3DV_META_TEXEL_BUFFER_COPY_CACHE_KEY_SIZE);
+   memcpy(dupkey, key, V3DV_META_TEXEL_BUFFER_COPY_CACHE_KEY_SIZE);
    _mesa_hash_table_insert(device->meta.texel_buffer_copy.cache[image_type],
-                           &key, *pipeline);
+                           dupkey, *pipeline);
 
    mtx_unlock(&device->meta.mtx);
    return true;