Debugger: va_list 'args' opened but not closed by va_end()

pointed out by cppcheck

Change-Id: Idf81666674c881ca9e00bf3985ed0dcf928c19d5
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4220
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

src/kits/debugger/util/Worker.cpp

@@ -139,6 +139,7 @@ Job::SetDescription(const char* format, ...)
 	va_list args;
 	va_start(args, format);
 	fDescription.SetToFormatVarArgs(format, args);
+	va_end(args);
 }