doCrypt() - check the error codes
Disabled (moved into the legacy provider) DES-CBC results in a crash, when setting key length.
Pick-to: 6.2 6.1 5.15
Change-Id: Ie0b49424f11d8042ebecebfd3b6346263f730551
Reviewed-by: Mårten Nordheim marten.nordheim@qt.io
(cherry picked from commit b4942f7f)