netfilter: nft_counter: fix erroneous return values

The nft_counter_init() and nft_counter_clone() functions should return
negative error value -ENOMEM instead of positive ENOMEM.
Signed-off-by: NAnton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nft_counter.c

@@ -100,7 +100,7 @@ static int nft_counter_init(const struct nft_ctx *ctx,
 
 	cpu_stats = netdev_alloc_pcpu_stats(struct nft_counter_percpu);
 	if (cpu_stats == NULL)
-		return ENOMEM;
+		return -ENOMEM;
 
 	preempt_disable();
 	this_cpu = this_cpu_ptr(cpu_stats);
@@ -138,7 +138,7 @@ static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src)
 	cpu_stats = __netdev_alloc_pcpu_stats(struct nft_counter_percpu,
 					      GFP_ATOMIC);
 	if (cpu_stats == NULL)
-		return ENOMEM;
+		return -ENOMEM;
 
 	preempt_disable();
 	this_cpu = this_cpu_ptr(cpu_stats);