tty: n_hdlc not atomic use tty->flags.
tty: n_hdlc not atomic use tty->flags.

N_HDLC can spoil tty->flags because use not atomic operations on tty->flags.
I use n_hdlc line discipline and it happens.

Signed-off-by: Ilya Zykov <482e68dbeed71dc76f78b5d1f0b9d00205bff675@ilyx.ru>
Acked-by: Alan Cox <91e38e63b890fbb214c8914809fde03c73e7f24d@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@suse.de>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs