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/bridge/netfilter/ebt_among.c b/net/bridge/netfilter/ebt_among.c
index 8a75d39..20068e0 100644
--- a/net/bridge/netfilter/ebt_among.c
+++ b/net/bridge/netfilter/ebt_among.c
@@ -190,17 +190,17 @@
 		pr_info("wrong size: %d against expected %d, rounded to %Zd\n",
 			em->match_size, expected_length,
 			EBT_ALIGN(expected_length));
-		return false;
+		return -EINVAL;
 	}
 	if (wh_dst && (err = ebt_mac_wormhash_check_integrity(wh_dst))) {
 		pr_info("dst integrity fail: %x\n", -err);
-		return false;
+		return -EINVAL;
 	}
 	if (wh_src && (err = ebt_mac_wormhash_check_integrity(wh_src))) {
 		pr_info("src integrity fail: %x\n", -err);
-		return false;
+		return -EINVAL;
 	}
-	return true;
+	return 0;
 }
 
 static struct xt_match ebt_among_mt_reg __read_mostly = {