When larval states are generated along with ACQUIRE messages, we should
use the sequence to find the corresponding larval state when creating
states with ADD_SA or ALLOC_SPI.

If we don't do that, then it may take down an unrelated larval state
with the same parameters (think different TCP sessions).  This not only
leaves behind a larval state that shouldn't be there, it may also cause
another ACQUIRE message to be sent unnecessarily.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>