crypto: inside-secure - do not process request if no command was issued

This patch adds a check in the SafeXcel dequeue function, to avoid
processing request further if no hardware command was issued. This can
happen in certain cases where the ->send() function caches all the data
that would have been send.

Fixes: 809778e0 ("crypto: inside-secure - fix hash when length is a multiple of a block")
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>