netfilter: nft_meta: use raw_smp_processor_id()

Using smp_processor_id() triggers warnings with PREEMPT_RCU. There is no
point in disabling preemption since we only collect the numeric value,
so use raw_smp_processor_id() instead.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nft_meta.c

@@ -153,7 +153,7 @@ void nft_meta_get_eval(const struct nft_expr *expr,
 		}
 		break;
 	case NFT_META_CPU:
-		dest->data[0] = smp_processor_id();
+		dest->data[0] = raw_smp_processor_id();
 		break;
 	case NFT_META_IIFGROUP:
 		if (in == NULL)