initfs: Use stty to drain output before reboot

To see all the messages during shutdown call stty cooked.

A side effect of setting any mode is it will call ioctl(TIOC_DRAIN)
to drain the buffers first without regard to any change in the mode.

Shutdown and flash update now show the final ouptut and "Rebooting"
message before the reboot system call.

Before:
+ set +x
Remaining mounts:
tmpfs / tmpfs rw,nosuid,nodev,mode=755 0 0
dev /dev devtmpfs rw,relatime,size=126384k,nr_inodes=31596,mode=755 0 0
proc /proc proc rw,relatime 0 0
sys /s

U-Boot 2013.07 (Feb 23 2016 - 10:21:23)

After:
+ set +x
Remaining mounts:
tmpfs / tmpfs rw,nosuid,nodev,mode=755 0 0
dev /dev devtmpfs rw,relatime,size=126384k,nr_inodes=31596,mode=755 0 0
proc /proc proc rw,relatime 0 0
sys /sys sysfs rw,relatime 0 0
tmpfs /run tmpfs rw,nosuid,nodev,mode=755 0 0
reboot: Restarting system

U-Boot 2013.07 (Feb 23 2016 - 10:21:23)

Signed-off-by: Milton Miller <miltonm@us.ibm.com>
1 file changed
tree: 190b32c8e688061e8b89e128b66e910d93ee89f9
  1. classes/
  2. common/
  3. conf/
  4. COPYING.apache-2.0
  5. COPYING.MIT
  6. LICENSE