arcmsr: make code more readable

[mkp: Fixed checkpatch whitespace warning]

Signed-off-by: Ching Huang <ching2048@areca.com.tw>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>