net: advance skb_defer_disable_key check in napi_consume_skb

net: advance skb_defer_disable_key check in napi_consume_skb

When net.core.skb_defer_max is adjusted to zero, napi_consume_skb()
shouldn't go into that deeper in skb_attempt_defer_free() because it adds
an additional pair of local_bh_enable/disable() which is evidently not
needed. Advancing the check of the static key saves more cycles and
benefits non defer case.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Link: https://patch.msgid.link/20260402034114.65766-1-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>