switch xattr_handler->set() to passing dentry and inode separately

preparation for similar switch in ->setxattr() (see the next commit for
rationale).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ext2/xattr_security.c b/fs/ext2/xattr_security.c
index 7fd3b86..7b9e9c1 100644
--- a/fs/ext2/xattr_security.c
+++ b/fs/ext2/xattr_security.c
@@ -18,10 +18,11 @@
 
 static int
 ext2_xattr_security_set(const struct xattr_handler *handler,
-			struct dentry *dentry, const char *name,
-			const void *value, size_t size, int flags)
+			struct dentry *unused, struct inode *inode,
+			const char *name, const void *value,
+			size_t size, int flags)
 {
-	return ext2_xattr_set(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
+	return ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY, name,
 			      value, size, flags);
 }