ext2: check err when partial != NULL

Check err when partial == NULL is meaningless because
partial == NULL means getting branch successfully without
error.

CC: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Chengguang Xu <[e-mail]>
Signed-off-by: Jan Kara <[e-mail]>

fs/ext2/inode.c

···
 		if (!partial) {
 			count++;
 			mutex_unlock(&ei->truncate_mutex);
-			if (err)
-				goto cleanup;
 			goto got_it;
+		}
+
+		if (err) {
+			mutex_unlock(&ei->truncate_mutex);
+			goto cleanup;
 		}
 	}