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/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index 6e6d536..e18da23 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -852,9 +852,8 @@
 		ret = PTR_ERR(root);
 		goto unacquire_priv_sbp;
 	}
-	sb->s_root = d_alloc_root(root);
+	sb->s_root = d_make_root(root);
 	if (!sb->s_root) {
-		iput(root);
 		befs_error(sb, "get root inode failed");
 		goto unacquire_priv_sbp;
 	}