Kernel: Simplify some if statements

Author: https://github.com/Hendiadyoin1
Commit: 23037d619a
Pull-request: https://github.com/SerenityOS/serenity/pull/11475

Kernel/GlobalProcessExposed.cpp

@@ -336,9 +336,7 @@ private:
     ProcFSSelfProcessDirectory();
     virtual bool acquire_link(KBufferBuilder& builder) override
     {
-        if (builder.appendff("{}", Process::current().pid().value()).is_error())
-            return false;
-        return true;
+        return !builder.appendff("{}", Process::current().pid().value()).is_error();
     }
 };