ecryptfs-migrate-home fails on subsequent runs, if first run fails due to wrong login password

[Daniel Holbert]

STEPS TO REPRODUCE:
 1. Create a temporary user without an encrypted home directory:
        sudo useradd -m testUser -p testPassword

 2. Run ecryptfs-migrate-home for that user
        sudo ecryptfs-migrate-home -u testUser

 3. ecryptfs-migrate-home will immediately prompt you for the user's password. Pretend you've forgotten it. Just hit "enter", or mistype the password.

 4. Now you've remembered the password! Repeat step 2.

ACTUAL RESULTS: ecryptfs-migrate-home fails, saying:
> If you already have some data in directory /home/.ecryptfs/testUser,
> please move all of these files and directories out of the way, and
> follow the instructions in:
> ecryptfs-setup-private --undo
>
> ERROR: /home/.ecryptfs/testUser is not empty, cannot continue.

EXPECTED RESULTS: ecryptfs-migrate-home should work -- no cruft should've been left behind by the first run. It should have prompted me for the user's password (and verified that it's correct) *before* setting up state that's going to break subsequent runs.