wifi: iwlwifi: Fix A-MSDU TSO preparation

wifi: iwlwifi: Fix A-MSDU TSO preparation

[ Upstream commit 3640dbc1f75ce15d128ea4af44226960d894f3fd ]

The TSO preparation assumed that the skb head contained the headers
while the rest of the data was in the fragments. Since this is not
always true, e.g., it is possible that the data was linearised, modify
the TSO preparation to start the data processing after the network
headers.

Fixes: 7f5e3038f029 ("wifi: iwlwifi: map entire SKB when sending AMSDUs")
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250209143303.75769a4769bf.Iaf79e8538093cdf8c446c292cc96164ad6498f61@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>