switch open-coded instances of d_make_root() to new helper

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index 06858d9..d8dc002 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -247,12 +247,9 @@
 	if (!ino)
 		goto fail_free;
 	root_inode = autofs4_get_inode(s, S_IFDIR | 0755);
-	if (!root_inode)
-		goto fail_ino;
-
-	root = d_alloc_root(root_inode);
+	root = d_make_root(root_inode);
 	if (!root)
-		goto fail_iput;
+		goto fail_ino;
 	pipe = NULL;
 
 	root->d_fsdata = ino;
@@ -317,9 +314,6 @@
 fail_dput:
 	dput(root);
 	goto fail_free;
-fail_iput:
-	printk("autofs: get root dentry failed\n");
-	iput(root_inode);
 fail_ino:
 	kfree(ino);
 fail_free: