netfilter: xt_osf: fix xt_osf_remove_callback() return value

Return a negative error value.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/xt_osf.c b/net/netfilter/xt_osf.c
index 63e1905..4d1a41b 100644
--- a/net/netfilter/xt_osf.c
+++ b/net/netfilter/xt_osf.c
@@ -118,7 +118,7 @@
 {
 	struct xt_osf_user_finger *f;
 	struct xt_osf_finger *sf;
-	int err = ENOENT;
+	int err = -ENOENT;
 
 	if (!osf_attrs[OSF_ATTR_FINGER])
 		return -EINVAL;