C#: Minor simplification.

Author: michaelnebel

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll

@@ -653,10 +653,7 @@ module LocalFlow {
       (
         scope = def.getExpr() and
         isSuccessor = true and
-        (
-          not def instanceof AssignableDefinitions::PatternDefinition or
-          def instanceof AssignableDefinitions::TopLevelPatternDefinition
-        )
+        not def instanceof AssignableDefinitions::PatternDefinition
         or
         scope = def.(AssignableDefinitions::TopLevelPatternDefinition).getMatch().(IsExpr) and
         isSuccessor = false