linux 'sim': buffer overflow after performing LOADST, SAVEST, SAVE on current Ubuntu 24.04.1

See https://forum.swissmicros.com/viewtopic.php?p=34066#p34066

How to reproduce:

• download and unzip https://gitlab.com/api/v4/projects/14055190/packages/generic/c47/00.109.02.06b5/c47-linux-00.109.02.06b5.zip
• cd c47-linux-00.109.02.06b5and ./c47
• IO -> LOADST, buffer overflow occurs after selection of state file

For comparison used 7e65e88c and make dist_linux. Using same steps with c47-linux.zip, but this error did not occur.