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/attr.c b/attr.c
index 375b5c0dbf..0b599334dd 100644
--- a/attr.c
+++ b/attr.c
@@ -61,10 +61,10 @@ struct attr_hash_entry {
 };
 
 /* attr_hashmap comparison function */
-static int attr_hash_entry_cmp(const void *UNUSED(cmp_data),
+static int attr_hash_entry_cmp(const void *cmp_data UNUSED,
 			       const struct hashmap_entry *eptr,
 			       const struct hashmap_entry *entry_or_key,
-			       const void *UNUSED(keydata))
+			       const void *keydata UNUSED)
 {
 	const struct attr_hash_entry *a, *b;