[OE-core] tinylogin ends up with group/user id 1000

[Kyle Farnsworth]

tinylogin installs the executable using the mode setting "-m 4755" which
sets the userID bit (-rwsr-xr-x).  From what I read that seems like the
right thing to do.  But when it gets added to the rootfs image it ends
up with a group and user id = 1000.  Then when getty attempts to login I
get this message:
    login: cannot set groups: Operations not permitted

I did enough debugging to find this occurs when it makes a syscall to
setgroups.  If I change the install to use mode "-m 0755" the group/user
id ends up being 0 and it works.

Where is the logic that determines group/user ids and why would it use
1000?  Can I override it?

Kyle