Bastien Nocera authored May 14, 2008 and Daniel Drake committed May 14, 2008

Make all of FPrintManager's struct members private,
warn of errors using a _get_error() function, as object
creation can never fail.

The only error possible shouldn't really be an error though,
as it only means that no devices will be enumerated, but it
could tell us about newly plugged devices instead.