xfrm: Fix ESN sequence number handling for IPsec GSO packets.

[ Upstream commit b8b549eec8187ac1b12075d69a2d84d89b5e811a ]

When IPsec offloading was introduced, we accidentally incremented
the sequence number counter on the xfrm_state by one packet
too much in the ESN case. This leads to a sequence number gap of
one packet after each GSO packet. Fix this by setting the sequence
number to the correct value.

Fixes: d7dbefc4 ("xfrm: Add xfrm_replay_overflow functions for offloading")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>