[clang-tidy] Enclose macro arguments in ()

Found with bugprone-macro-parentheses

Signed-off-by: Rosen Penev <rosenp@gmail.com>

src/builtin.cpp

@@ -222,7 +222,7 @@ static int builtin_generic(parser_t &parser, io_streams_t &streams, wchar_t **ar
 
 // How many bytes we read() at once.
 // Since this is just for counting, it can be massive.
-#define COUNT_CHUNK_SIZE 512 * 256
+#define COUNT_CHUNK_SIZE (512 * 256)
 /// Implementation of the builtin count command, used to count the number of arguments sent to it.
 static int builtin_count(parser_t &parser, io_streams_t &streams, wchar_t **argv) {
     UNUSED(parser);