mpt3sas: issue_reset is uninitialized

The "issue_reset" can be used uninitialized.  It should be set to false
at the start.

Also I cleaned up the types a little by using bool.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>