Optimized filesystem.name() / Fix filesystem.copy() (#2432)

* Fixed possible error reporting bug in filesystem.copy()

Made local data initialize to false. Previously was nil and if the function was unable to open either file, this would cause the function to return true as its first value. data becomes nil when copying is finished, so this sorts itself out.
Added arg checking to filesystem.name

src/main/resources/assets/opencomputers/loot/openos/lib/filesystem.lua

@@ -282,6 +282,7 @@ function filesystem.path(path)
 end
 
 function filesystem.name(path)
+  checkArg(1, path, "string")
   local parts = segments(path)
   return parts[#parts]
 end
@@ -436,7 +437,7 @@ function filesystem.rename(oldPath, newPath)
 end
 
 function filesystem.copy(fromPath, toPath)
-  local data
+  local data = false
   local input, reason = filesystem.open(fromPath, "rb")
   if input then
     local output, reason = filesystem.open(toPath, "wb")