scsi: hpsa: fix an uninitialized read and dereference of pointer dev

Currently the check for a lockup_detected failure exits via the label
return_reset_status that reads and dereferences an uninitialized pointer
dev.  Fix this by ensuring dev is inintialized to null.

Addresses-Coverity: ("Uninitialized pointer read")
Fixes: 14991a5bade5 ("scsi: hpsa: correct device resets")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Acked-by: NDon Brace <don.brace@microsemi.com>
Reviewed-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hpsa.c

@@ -5947,7 +5947,7 @@ static int hpsa_eh_device_reset_handler(struct scsi_cmnd *scsicmd)
 	int rc = SUCCESS;
 	int i;
 	struct ctlr_info *h;
-	struct hpsa_scsi_dev_t *dev;
+	struct hpsa_scsi_dev_t *dev = NULL;
 	u8 reset_type;
 	char msg[48];
 	unsigned long flags;