object-file: pass filename to fsync_or_die

If we die while trying to fsync a loose object file, pass the actual
filename we're trying to sync. This is likely to be more helpful for a
user trying to diagnose the cause of the failure than the former
'loose object file' string. It also sidesteps any concerns about
translating the die message differently for loose objects versus
something else that has a real path.

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

object-file.c

@@ -1888,16 +1888,16 @@ void hash_object_file(const struct git_hash_algo *algo, const void *buf,
 }
 
 /* Finalize a file on disk, and close it. */
-static void close_loose_object(int fd)
+static void close_loose_object(int fd, const char *filename)
 {
 	if (the_repository->objects->odb->will_destroy)
 		goto out;
 
 	if (fsync_object_files > 0)
-		fsync_or_die(fd, "loose object file");
+		fsync_or_die(fd, filename);
 	else
 		fsync_component_or_die(FSYNC_COMPONENT_LOOSE_OBJECT, fd,
-				       "loose object file");
+				       filename);
 
 out:
 	if (close(fd) != 0)
@@ -2011,7 +2011,7 @@ static int write_loose_object(const struct object_id *oid, char *hdr,
 		die(_("confused by unstable object source data for %s"),
 		    oid_to_hex(oid));
 
-	close_loose_object(fd);
+	close_loose_object(fd, tmp_file.buf);
 
 	if (mtime) {
 		struct utimbuf utb;