[clang][dataflow] Remove unused lambda capture

[krasimir]

I'll submit this for you.

clang/lib/Sema/SemaExpr.cpp

 
 /// Compute the nullability of a conditional expression.
 static QualType computeConditionalNullability(QualType ResTy, bool IsBin,
                                               QualType LHSTy, QualType RHSTy,
                                               ASTContext &Ctx) {
   if (!ResTy->isAnyPointerType())
     return ResTy;
 
-  auto GetNullability = [&Ctx](QualType Ty) {
+  auto GetNullability = [](QualType Ty) {
     Optional<NullabilityKind> Kind = Ty->getNullability();
     if (Kind) {
       // For our purposes, treat _Nullable_result as _Nullable.
       if (*Kind == NullabilityKind::NullableResult)
         return NullabilityKind::Nullable;
       return *Kind;
     }
     return NullabilityKind::Unspecified;