megaraid_sas: complete outstanding IOCTLs before killing adapter

Driver calls megasas_complete_cmd() to call wake_up() for each MFI frame
that was issued through the ioctl() interface prior to the kill adapter.
This ensures userspace ioctl() system calls issued just before a kill
adapter don't get stuck in wait state and IOCTLs are returned to
the application.

Cc: <stable@vger.kernel.org>
Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Chaitra Basappa <chaitra.basappa@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>