MT#55283 add a few more missing nft cleanups

These don't actually do anything right now as these function don't do an
early return, but having these in place will make things more future
proof.

Change-Id: I05b82a4366847e0eff1d1392885cf086516df053

daemon/nftables.c

@@ -438,7 +438,7 @@ static const char *input_immediate(struct nftnl_rule *r, int family, struct add_
 	if (err)
 		return err;
 
-	struct nftnl_expr *e = nftnl_expr_alloc("immediate");
+	g_autoptr(_nftnl_expr) e = nftnl_expr_alloc("immediate");
 	if (!e)
 		return "failed to allocate immediate expr";
 
@@ -447,13 +447,14 @@ static const char *input_immediate(struct nftnl_rule *r, int family, struct add_
 	nftnl_expr_set_str(e, NFTNL_EXPR_IMM_CHAIN, callbacks->chain);
 
 	nftnl_rule_add_expr(r, e);
+	e = NULL;
 
 	return NULL;
 }
 
 
 static const char *rtpe_target_base(struct nftnl_rule *r, struct add_rule_callbacks *callbacks) {
-	struct nftnl_expr *e = nftnl_expr_alloc("target");
+	g_autoptr(_nftnl_expr) e = nftnl_expr_alloc("target");
 	if (!e)
 		return "failed to allocate target expr for RTPENGINE";
 
@@ -468,6 +469,7 @@ static const char *rtpe_target_base(struct nftnl_rule *r, struct add_rule_callba
 	nftnl_expr_set(e, NFTNL_EXPR_TG_INFO, info, sizeof(*info));
 
 	nftnl_rule_add_expr(r, e);
+	e = NULL;
 
 	return NULL;
 }
@@ -480,10 +482,11 @@ static const char *rtpe_target(struct nftnl_rule *r, int family, struct add_rule
 	if (err)
 		return err;
 
-	struct nftnl_expr *e = nftnl_expr_alloc("counter");
+	g_autoptr(_nftnl_expr) e = nftnl_expr_alloc("counter");
 	if (!e)
 		return "failed to allocate counter expr for RTPENGINE";
 	nftnl_rule_add_expr(r, e);
+	e = NULL;
 
 	return NULL;
 }