lightnvm: pblk: use vfree to free metadata on error path

As chunk metadata is allocated using vmalloc, we need to free it
using vfree.

Fixes: 090ee26f ("lightnvm: use internal allocation for chunk log page")
Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/lightnvm/pblk-core.c

@@ -141,7 +141,7 @@ struct nvm_chk_meta *pblk_get_chunk_meta(struct pblk *pblk)
 
 	ret = nvm_get_chunk_meta(dev, ppa, geo->all_chunks, meta);
 	if (ret) {
-		kfree(meta);
+		vfree(meta);
 		return ERR_PTR(-EIO);
 	}