crypto: api - Call crypto_schedule_test outside of mutex

There is no need to hold the crypto mutex when scheduling a self-
test.  In fact prior to the patch introducing asynchronous testing,
this was done outside of the locked area.

Move the crypto_schedule_test call back out of the locked area.

Also move crypto_remove_final to the else branch under the schedule-
test call as the list of algorithms to be removed is non-empty only
when the test larval is NULL (i.e., testing is disabled).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>