If you did not use the VISA serial calls in Linux, then you need to include the serial port driver (serp.drv in Windows) in the same directory as your built application.
However; if you did use the VISA serial, you will need the VISA runtime engine, which should be on your LabVIEW for LInux CD.
If you do not find it there, or on the website, contact NI for assistance at ni.com/ask. Also check on the linux support pages at ni.com/linux.