qla2xxx: release request queue reservation.

Request IOCB queue element(s) is reserved during
good path IO.  Under error condition such as unable
to allocate IOCB handle condition, the IOCB count
that was reserved is not released.

Cc: <stable@vger.kernel.org> # v3.18+
Signed-off-by: Quinn Tran <quinn.tran@qlogic.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>