scsi: qla2xxx: Always check the return value of qla24xx_get_isp_stats()

scsi: qla2xxx: Always check the return value of qla24xx_get_isp_stats()

This patch fixes the following Coverity warning:

    CID 361199 (#1 of 1): Unchecked return value (CHECKED_RETURN)
    3. check_return: Calling qla24xx_get_isp_stats without checking return
    value (as is done elsewhere 4 out of 5 times).

Link: https://lore.kernel.org/r/20210320232359.941-7-bvanassche@acm.org
Cc: Quinn Tran <qutran@marvell.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Himanshu Madhani <himanshu.madhani@oracle.com>
Cc: Daniel Wagner <dwagner@suse.de>
Cc: Lee Duncan <lduncan@suse.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>