SPDY: fixed possible uninitialized memory access.
SPDY: fixed possible uninitialized memory access.

The frame->stream pointer should always be initialized for control frames since
the check against it can be performed in ngx_http_spdy_filter_cleanup().

firebase/nginx,hy0kl/nginx,firebase/nginx,hy0kl/nginx,firebase/nginx,firebase/nginx,hy0kl/nginx