netfilter: xtables: change matches to return error code

The following semantic patch does part of the transformation:
// <smpl>
@ rule1 @
struct xt_match ops;
identifier check;
@@
 ops.checkentry = check;

@@
identifier rule1.check;
@@
 check(...) { <...
-return true;
+return 0;
 ...> }

@@
identifier rule1.check;
@@
 check(...) { <...
-return false;
+return -EINVAL;
 ...> }
// </smpl>

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/net/netfilter/xt_connbytes.c b/net/netfilter/xt_connbytes.c
index 136ef4c..bf8e286 100644
--- a/net/netfilter/xt_connbytes.c
+++ b/net/netfilter/xt_connbytes.c
@@ -100,20 +100,20 @@
 	if (sinfo->what != XT_CONNBYTES_PKTS &&
 	    sinfo->what != XT_CONNBYTES_BYTES &&
 	    sinfo->what != XT_CONNBYTES_AVGPKT)
-		return false;
+		return -EINVAL;
 
 	if (sinfo->direction != XT_CONNBYTES_DIR_ORIGINAL &&
 	    sinfo->direction != XT_CONNBYTES_DIR_REPLY &&
 	    sinfo->direction != XT_CONNBYTES_DIR_BOTH)
-		return false;
+		return -EINVAL;
 
 	if (nf_ct_l3proto_try_module_get(par->family) < 0) {
 		pr_info("cannot load conntrack support for proto=%u\n",
 			par->family);
-		return false;
+		return -EINVAL;
 	}
 
-	return true;
+	return 0;
 }
 
 static void connbytes_mt_destroy(const struct xt_mtdtor_param *par)