don't bother with ->d_inode->i_sb - it's always equal to ->d_sb

... and neither can ever be NULL

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index b30a4a6..4cfb4d9f 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -78,7 +78,7 @@
 {
 	struct dentry *dentry, *alias;
 	struct inode *inode;
-	struct super_block *sb = d_inode(parent)->i_sb;
+	struct super_block *sb = parent->d_sb;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 
 	cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);