liquidio: CN23XX: fix a loop timeout

This is supposed to loop 1000 times and then give up.  The problem is
it's a post-op and after the loop we test if "loop" is zero when really
it would be -1.  Fix this by making it a pre-op.

Fixes: 1b7c55c4

 ("liquidio: CN23XX queue manipulation")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>