ath6kl: unblock fwlog_block_read() on exit

Complete the waiting fwlog_block_read on debugfs cleanup, otherwise
userspace and module unload might softlock.

Signed-off-by: Thomas Pedersen <c_tpeder@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath6kl/debug.c

@@ -1824,6 +1824,7 @@ int ath6kl_debug_init_fs(struct ath6kl *ar)
 void ath6kl_debug_cleanup(struct ath6kl *ar)
 {
 	skb_queue_purge(&ar->debug.fwlog_queue);
+	complete(&ar->debug.fwlog_completion);
 	kfree(ar->debug.roam_tbl);
 }