AK+Kernel+Userland: Enable some more compiletime format string checks

This enables format string checks for three more functions:
- String::formatted()
- Builder::appendff()
- KBufferBuilder::appendff()

1 files changed, 2 insertions, 2 deletions

diff --git a/AK/StringBuilder.h b/AK/StringBuilder.h
index a430f3e95a..e578ca885b 100644
--- a/AK/StringBuilder.h
+++ b/AK/StringBuilder.h
@@ -52,9 +52,9 @@ public:
     void append_escaped_for_json(const StringView&);
 
     template<typename... Parameters>
-    void appendff(StringView fmtstr, const Parameters&... parameters)
+    void appendff(CheckedFormatString<Parameters...>&& fmtstr, const Parameters&... parameters)
     {
-        vformat(*this, fmtstr, VariadicFormatParams { parameters... });
+        vformat(*this, fmtstr.view(), VariadicFormatParams { parameters... });
     }
 
     String build() const;