iwl4965: do not process non-QOS frames on txq->sched_retry path

We have already WARN_ON(!qc) for non-QOS frame on txq->sched_retry path,
but we continue to process, what makes no sense since tid is not
initialized. Non QOS frame should never happen when aggregation
is enabled on queue, so do not process that.

Patch should fix smatch warning:
drivers/net/wireless/intel/iwlegacy/4965-mac.c:2822 il4965_hdl_tx() error: uninitialized symbol 'tid'.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210119100621.439134-1-stf_xl@wp.pl