Fix loop in ecryptfs-manager when there are no options (LP: #1695767)
Reproduce case: 1) User doesn't install openssl. 2) Run ecryptfs-manager and make selection 3. It goes in the infinite loop...which means whatever selection you enter next cannot end this command or alter your option.
Explanation for the patch: Adding several lines to take such a case into consideration, through testing whether "num_transitions" is set to zero or not we could prevent the infinite loop. If it is set to zero, it will return -EINVAL because "num_transitions" means how many options this command could show to users and zero means that user has no option to choose.
[tyhicks: Print to stderr, adjust error message, and add changelog entry]