scsi: mpt3sas: clear release bit when buffer reregistered

Clear MPT3_DIAG_BUFFER_IS_RELEASED bit once diag buffer is re-registered
after reading the buffer, else driver won't release the buffer and return
the 'diag release' command with -EINVAL status saying that buffer is
already released.

Link: https://lore.kernel.org/r/1568379890-18347-7-git-send-email-sreekanth.reddy@broadcom.com


Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>