fs/squashfs: sqfs_probe: use sqfs_decompressor_init() return value

sqfs_decompressor_init() returns a value, so it's better to use it than
to force the return value to EINVAL (it could be ENOMEM)
Reviewed-by: Joao Marcos Costa <jmcosta944@gmail.com>
Signed-off-by: Richard Genoud <richard.genoud@posteo.net>

fs/squashfs/sqfs.c

@@ -1097,9 +1097,7 @@ int sqfs_probe(struct blk_desc *fs_dev_desc, struct disk_partition *fs_partition
 	ctxt.sblk = sblk;
 
 	ret = sqfs_decompressor_init(&ctxt);
-
 	if (ret) {
-		ret = -EINVAL;
 		goto error;
 	}