OctOS: Improve error handling

Commands run and code called with the `lua` command would not throw an error if it was unsucessful.

octos/exec/lua.lua

@@ -1,8 +1,8 @@
 local params = ...
 local code = (table.concat(params, " "))
 
-local res = run(code)
+local ok, res = run(code)
 
-if not res then
-  print("Error: Could not run `"..code.."`")
+if not ok then
+  print("Error: "..res)
 end

octos/main.lua

@@ -10,7 +10,11 @@ if input[1] ~= "" then
     -- Remove first param
     table.remove(input, 1)
 
-    fs.run(binentry.exec, input)
+    local ok, res = fs.run(binentry.exec, input)
+
+    if not ok then
+      print("Error: "..res)
+    end
   else
     print(input[1]..": command not found")
   end