netfilter: nf_tables: refactor deprecated strncpy

Prefer `strscpy_pad` over `strncpy`.
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>

net/netfilter/nft_fib.c

@@ -151,7 +151,7 @@ void nft_fib_store_result(void *reg, const struct nft_fib *priv,
 		if (priv->flags & NFTA_FIB_F_PRESENT)
 			*dreg = !!dev;
 		else
-			strncpy(reg, dev ? dev->name : "", IFNAMSIZ);
+			strscpy_pad(reg, dev ? dev->name : "", IFNAMSIZ);
 		break;
 	default:
 		WARN_ON_ONCE(1);