serialization savegame example docs: Remove duplicate "each"

Pick-to: 6.10 6.8 6.5
Change-Id: I0fbb11d8828e09cdfa6651b799134561ed076fdd
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>
(cherry picked from commit 856f685)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

Author: owolff

examples/corelib/serialization/savegame/doc/src/savegame.qdoc

@@ -92,7 +92,7 @@
 
     \snippet serialization/savegame/level.h 0
 
-    We want the levels in our game to each each have several NPCs, so we keep a QList
+    We want the levels in our game to each have several NPCs, so we keep a QList
     of Character objects. We also provide the familiar fromJson() and toJson()
     functions.