hashmap_put takes "struct hashmap_entry *"

This is less error-prone than "void *" as the compiler now
detects invalid types being passed.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

oidmap.c

@@ -51,5 +51,5 @@ void *oidmap_put(struct oidmap *map, void *entry)
 		oidmap_init(map, 0);
 
 	hashmap_entry_init(&to_put->internal_entry, oidhash(&to_put->oid));
-	return hashmap_put(&map->map, to_put);
+	return hashmap_put(&map->map, &to_put->internal_entry);
 }