[XFS] convert xfs to use ERR_CAST

Looks like somehow xfs got missed in the conversion that took place in
e231c2ee, "Convert ERR_PTR(PTR_ERR(p))
instances to ERR_CAST(p)
<http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit
diff;h=e231c2ee>"

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31757a
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

fs/xfs/linux-2.6/xfs_export.c

@@ -167,7 +167,7 @@ xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
 	if (!inode)
 		return NULL;
 	if (IS_ERR(inode))
-		return ERR_PTR(PTR_ERR(inode));
+		return ERR_CAST(inode);
 	result = d_alloc_anon(inode);
 	if (!result) {
 		iput(inode);
@@ -198,7 +198,7 @@ xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
 	if (!inode)
 		return NULL;
 	if (IS_ERR(inode))
-		return ERR_PTR(PTR_ERR(inode));
+		return ERR_CAST(inode);
 	result = d_alloc_anon(inode);
 	if (!result) {
 		iput(inode);