[darwin-framework-tool] Fix a typo when dumping value as string (#39793)

diff --git a/examples/darwin-framework-tool/commands/common/CHIPCommandBridge.mm b/examples/darwin-framework-tool/commands/common/CHIPCommandBridge.mm
index 0bbeea3..968d817 100644
--- a/examples/darwin-framework-tool/commands/common/CHIPCommandBridge.mm
+++ b/examples/darwin-framework-tool/commands/common/CHIPCommandBridge.mm
@@ -51,7 +51,7 @@
 namespace {
 NSString * ToNSString(const chip::Optional<chip::app::DataModel::Nullable<char *>> & string)
 {
-    if (!string.HasValue() && string.Value().IsNull()) {
+    if (!string.HasValue() || string.Value().IsNull()) {
         return nil;
     }