hash: drop (mostly) unused is_empty_{blob,tree}_sha1() functions

The functions `is_empty_{blob,tree}_sha1()` are mostly unused, except
for a single callsite in "read-cache.c". Most callsites have long since
been converted to use the equivalents that accept a `struct object_id`
instead of a string.

Adapt the remaining callsite and drop those functions.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

hash.h

@@ -84,21 +84,11 @@ static inline void oidread(struct object_id *oid, const unsigned char *hash)
 	oidread_algop(oid, hash, the_hash_algo);
 }
 
-static inline int is_empty_blob_sha1(const unsigned char *sha1)
-{
-	return hasheq(sha1, the_hash_algo->empty_blob->hash);
-}
-
 static inline int is_empty_blob_oid(const struct object_id *oid)
 {
 	return oideq(oid, the_hash_algo->empty_blob);
 }
 
-static inline int is_empty_tree_sha1(const unsigned char *sha1)
-{
-	return hasheq(sha1, the_hash_algo->empty_tree->hash);
-}
-
 static inline int is_empty_tree_oid(const struct object_id *oid)
 {
 	return oideq(oid, the_hash_algo->empty_tree);

read-cache.c

@@ -337,7 +337,7 @@ static int ce_match_stat_basic(const struct cache_entry *ce, struct stat *st)
 
 	/* Racily smudged entry? */
 	if (!ce->ce_stat_data.sd_size) {
-		if (!is_empty_blob_sha1(ce->oid.hash))
+		if (!is_empty_blob_oid(&ce->oid))
 			changed |= DATA_CHANGED;
 	}