xattr_handler: pass dentry and inode as separate arguments of ->get()

... and do not assume they are already attached to each other

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ext2/xattr_user.c b/fs/ext2/xattr_user.c
index 72a2a96..1fafd27 100644
--- a/fs/ext2/xattr_user.c
+++ b/fs/ext2/xattr_user.c
@@ -18,12 +18,12 @@
 
 static int
 ext2_xattr_user_get(const struct xattr_handler *handler,
-		    struct dentry *dentry, const char *name,
-		    void *buffer, size_t size)
+		    struct dentry *unused, struct inode *inode,
+		    const char *name, void *buffer, size_t size)
 {
-	if (!test_opt(dentry->d_sb, XATTR_USER))
+	if (!test_opt(inode->i_sb, XATTR_USER))
 		return -EOPNOTSUPP;
-	return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_USER,
+	return ext2_xattr_get(inode, EXT2_XATTR_INDEX_USER,
 			      name, buffer, size);
 }