sysvinit-inittab: support non-busybox-getty on serial consoles
Busybox' getty has code to try to make itself a session leader,
whereas util-linux' agetty doesn't. It expects this to happen
from outside.
When getty is not a session leader, many things don't work on
the serial console, e.g. setting the terminal process group,
job control doesn't work, etc.
Executing image tests also fails with AssertionErrors, because
Feb 5 16:12:55 qemuarm getty[590]: /dev/ttyAMA1: cannot get controlling tty: Operation not permitted
Feb 5 16:12:55 qemuarm getty[590]: /dev/ttyAMA1: cannot set process group: Inappropriate ioctl for device
Update the start_getty script to invoke getty via the setsid
utility if needed, i.e. if /sbin/getty is not busybox getty.
[YOCTO #13058]
Signed-off-by: André Draszik <andre.draszik@jci.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
