[chore] setupkoenv: output some info about library loading (#3857)

That way it's always available.

Refrences #3853

setupkoenv.lua

@@ -19,13 +19,16 @@ end
 local ffi_load = ffi.load
 -- patch ffi.load for thirdparty luajit libraries
 ffi.load = function(lib)
+    io.write("ffi.load: ", lib, "\n")
     local loaded, re = pcall(ffi_load, lib)
     if loaded then return re end
 
     local lib_path = package.searchpath(lib, "./lib?.so;./libs/lib?.so;./libs/lib?.so.1")
+
     if not lib_path then
         error('Not able to load dynamic library: ' .. lib)
     else
+        io.write("ffi.load (assisted searchpath): ", lib_path, "\n")
         return ffi_load(lib_path)
     end
 end