Fix a bug in Measure::createEndBarLines().

Fix a bug in Measure::createEndBarLines().

A typo in function Measure::createEndBarLines() was creating a problem (additional bar lines not created when a mensurstrich span style was reduced at a normal span style).
At the same time, the typo was hiding another, perhaps more serious, bug: in some cases, extra bar lines were created for staves spanned by multi-staff bar lines.

Corrected.