xfrm: fix a race in xfrm_state_lookup_byspi
xfrm: fix a race in xfrm_state_lookup_byspi

The returned xfrm_state should be hold before unlock xfrm_state_lock,
otherwise the returned xfrm_state maybe be released.

Fixes: c454997e6[{pktgen, xfrm} Introduce xfrm_state_lookup_byspi..]
Cc: Fan Du <98b5df125785ddebbf642f8cf9f43d3980ddc694@intel.com>
Signed-off-by: Li RongQing <81c2f95e9d1350da984a3ef03e964ca9a6cbc5c2@gmail.com>
Acked-by: Fan Du <98b5df125785ddebbf642f8cf9f43d3980ddc694@intel.com>
Signed-off-by: Steffen Klassert <66deb1d63f85161cc287ce2bac0c65cb5ae958a7@secunet.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs