If the user doesn't create a swap partition on low
memory computers, the installer will notify about it.
So the partitioning has to be changed. Assuming the
user has already chosen some mountpoints before re-
partitioning, this is where the installer fails, it
remembers what mountpoints were chosen. If the user
edits the table so that the new swap device gets the
name of an already assigned device, the installer
doesn't let the mountpoint be changed as it's handling
a swap device which is not supposed to be mounted.