The snd_seq_queue struct contains various flags in the bit fields.
Those are categorized to two different use cases, both of which are
protected by different spinlocks.  That implies that there are still
potential risks of the bad operations for bit fields by concurrent
accesses.

For addressing the problem, this patch rearranges those flags to be
a standard bool instead of a bit field.

Reported-by: syzbot+63cbe31877bb80ef58f5@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20201206083456.21110-1-tiwai@suse.deSigned-off-by: NTakashi Iwai <tiwai@suse.de>