kernel: fix copy&paste mistake in bridge offload code

Signed-off-by: Felix Fietkau <[email protected]>

target/linux/generic/hack-5.10/600-bridge_offload.patch

@@ -428,7 +428,7 @@
 +		goto out;
 +
 +	inp = br_port_get_rcu(dev);
-+	if (!p)
++	if (!inp)
 +		goto out;
 +
 +	vg = nbp_vlan_group_rcu(inp);