Made sure to initialize the entire ngx_file_t structure.

Found by Coverity.

src/core/ngx_cycle.c

diff --git a/src/core/ngx_cycle.c b/src/core/ngx_cycle.c
index e5468ae..facf068 100644
--- a/src/core/ngx_cycle.c
+++ b/src/core/ngx_cycle.c
@@ -1038,6 +1038,8 @@
 
     ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
 
+    ngx_memzero(&file, sizeof(ngx_file_t));
+
     file.name = ccf->pid;
     file.log = cycle->log;