use already given variable

src/http/ngx_http_upstream.c

diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index e72daff..9d86914 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -562,8 +562,8 @@
 
     u->cacheable = 1;
 
-    c->min_uses = r->upstream->conf->cache_min_uses;
-    c->body_start = r->upstream->conf->buffer_size;
+    c->min_uses = u->conf->cache_min_uses;
+    c->body_start = u->conf->buffer_size;
     c->file_cache = u->conf->cache->data;
 
     rc = ngx_http_file_cache_open(r);