We currently catch any exceptions that may occur when the card reader is
initialized. Then we print the exception string or the exception type
when no string is available. However, a failure during the reader
initialization is usually a severe problem, so a traceback would provde
a lot of helpful information to debug the issue. So lets not catch any
exceptions at this level so that we get the full backtrace.
Related: OS#6210
Change-Id: I4c4807576fe63cf71a7d33b243a3f8fea0b7ff23