hashmap_add 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>

builtin/describe.c

@@ -124,7 +124,7 @@ static void add_to_known_names(const char *path,
 			e = xmalloc(sizeof(struct commit_name));
 			oidcpy(&e->peeled, peeled);
 			hashmap_entry_init(&e->entry, oidhash(peeled));
-			hashmap_add(&names, e);
+			hashmap_add(&names, &e->entry);
 			e->path = NULL;
 		}
 		e->tag = tag;