block: Fix a memory leak in bdev_open_by_dev()

If we early exit here, 'handle' needs to be freed, or some memory leaks.

Fixes: ed5cc702 ("block: Add config option to not allow writing to mounted devices")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/8eaec334781e695810aaa383b55de00ca4ab1352.1703439383.git.christophe.jaillet@wanadoo.frReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>

block/bdev.c

@@ -828,8 +828,10 @@ struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder,
 		goto free_handle;
 
 	/* Blocking writes requires exclusive opener */
-	if (mode & BLK_OPEN_RESTRICT_WRITES && !holder)
-		return ERR_PTR(-EINVAL);
+	if (mode & BLK_OPEN_RESTRICT_WRITES && !holder) {
+		ret = -EINVAL;
+		goto free_handle;
+	}
 
 	bdev = blkdev_get_no_open(dev);
 	if (!bdev) {