style fix
diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index 005c597..4967ad6 100644
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -417,7 +417,7 @@
     if (fcn == NULL) {
         ngx_shmtx_unlock(&cache->shpool->mutex);
 
-        ngx_http_file_cache_forced_expire(cache);
+        (void) ngx_http_file_cache_forced_expire(cache);
 
         ngx_shmtx_lock(&cache->shpool->mutex);