pnfs/flexfiles: Fix memory leak in nfs4_ff_alloc_deviceid_node()

In nfs4_ff_alloc_deviceid_node(), if the allocation for ds_versions fails,
the function jumps to the out_scratch label without freeing the already
allocated dsaddrs list, leading to a memory leak.

Fix this by jumping to the out_err_drain_dsaddrs label, which properly
frees the dsaddrs list before cleaning up other resources.

Fixes: d67ae82 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Author: GoodLuck612

fs/nfs/flexfilelayout/flexfilelayoutdev.c

@@ -103,7 +103,7 @@ nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
 			      sizeof(struct nfs4_ff_ds_version),
 			      gfp_flags);
 	if (!ds_versions)
-		goto out_scratch;
+		goto out_err_drain_dsaddrs;
 
 	for (i = 0; i < version_count; i++) {
 		/* 20 = version(4) + minor_version(4) + rsize(4) + wsize(4) +