Fix the logic for decoding modifiers map in Wayland text input protocol

Correctly check for the flags in the modifiers map when we get it from the compositor, instead of modifying the map in the for loop conditional.

[ChangeLog][QWaylandInputContext] Fix modifiers map decoding logic when receiving the map from the compositor.

Fixes: QTBUG-97094 Pick-to: 6.2 5.15 5.12 Change-Id: Idad19f7b1f4560d40abbb5b31032360cfe915261 Reviewed-by: Paul Olav Tvete paul.tvete@qt.io