Bugfix: open_file_cache did not update file info on retest.

If file inode was not changed, cached file information was not updated
on retest.  As a result stale information might be cached forever if file
attributes was changed and/or file was extended.

This fix also makes obsolete r4077 change of is_directio flag handling,
since this flag is updated together with other file information.
diff --git a/src/core/ngx_open_file_cache.c b/src/core/ngx_open_file_cache.c
index 1cce9e9..1306d14 100644
--- a/src/core/ngx_open_file_cache.c
+++ b/src/core/ngx_open_file_cache.c
@@ -284,15 +284,11 @@
 
             if (of->uniq == file->uniq) {
 
-                file->count++;
-
                 if (file->event) {
                     file->use_event = 1;
                 }
 
-                of->is_directio = file->is_directio;
-
-                goto renew;
+                goto update;
             }
 
             /* file was changed */
@@ -396,8 +392,6 @@
         }
     }
 
-renew:
-
     file->created = now;
 
 found: