net: fix GRO skb truesize update

net: fix GRO skb truesize update

commit 0ae4b79a6c63 ("skbuff: allow 'slow_gro' for skb carring sock
reference") introduces a serious regression at the GRO layer setting
the wrong truesize for stolen-head skbs.

Restore the correct truesize: SKB_DATA_ALIGN(...) instead of
SKB_TRUESIZE(...)

Reported-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Fixes: 0ae4b79a6c63 ("skbuff: allow 'slow_gro' for skb carring sock reference")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Tested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>