[media] rainshadow-cec: use strlcat instead of strncat
gcc warns about an obviously incorrect use of strncat():
drivers/media/usb/rainshadow-cec/rainshadow-cec.c: In function 'rain_cec_adap_transmit':
drivers/media/usb/rainshadow-cec/rainshadow-cec.c:299:4: error: specified bound 48 equals the size of the destination [-Werror=stringop-overflow=]
It seems that strlcat was intended here, and using that makes the
code correct.