Fix export decoration of Lua module
Fix export decoration of Lua module

Add missing export decoration for Lua module entry point. This fixes the
Lua module that stopped working when ELF hidden visibility was enabled.
(I'm not sure about Windows, as I don't have Lua on Windows, but I
suspect it never worked on Windows.)

adeschamps/lcm,bluesquall/lcm,bluesquall/lcm,bluesquall/lcm,adeschamps/lcm,adeschamps/lcm,adeschamps/lcm,adeschamps/lcm,lcm-proj/lcm,lcm-proj/lcm,bluesquall/lcm,lcm-proj/lcm,lcm-proj/lcm,adeschamps/lcm,lcm-proj/lcm,adeschamps/lcm,lcm-proj/lcm,adeschamps/lcm,bluesquall/lcm,bluesquall/lcm,bluesquall/lcm,lcm-proj/lcm,lcm-proj/lcm