git-compat-util.h: use "UNUSED", not "UNUSED(var)"

As reported in [1] the "UNUSED(var)" macro introduced in
2174b8c75de (Merge branch 'jk/unused-annotation' into next,
2022-08-24) breaks coccinelle's parsing of our sources in files where
it occurs.

Let's instead partially go with the approach suggested in [2] of
making this not take an argument. As noted in [1] "coccinelle" will
ignore such tokens in argument lists that it doesn't know about, and
it's less of a surprise to syntax highlighters.

This undoes the "help us notice when a parameter marked as unused is
actually use" part of 9b240347543 (git-compat-util: add UNUSED macro,
2022-08-19), a subsequent commit will further tweak the macro to
implement a replacement for that functionality.

1. https://lore.kernel.org/git/220825.86ilmg4mil.gmgdl@evledraar.gmail.com/
2. https://lore.kernel.org/git/220819.868rnk54ju.gmgdl@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/convert.c b/convert.c
index 25d89fa83b..95e6a5244f 100644
--- a/convert.c
+++ b/convert.c
@@ -619,7 +619,7 @@ struct filter_params {
 	const char *path;
 };
 
-static int filter_buffer_or_fd(int UNUSED(in), int out, void *data)
+static int filter_buffer_or_fd(int in UNUSED, int out, void *data)
 {
 	/*
 	 * Spawn cmd and feed the buffer contents through its stdin.
@@ -1008,7 +1008,7 @@ static int apply_filter(const char *path, const char *src, size_t len,
 	return 0;
 }
 
-static int read_convert_config(const char *var, const char *value, void *UNUSED(cb))
+static int read_convert_config(const char *var, const char *value, void *cb UNUSED)
 {
 	const char *key, *name;
 	size_t namelen;