Use the macro PRIu64 as format symbol to print uint64.
It could work well on both 32 bits and 64 bits without any warning.
Enhance the fastsocket ioctl function
Use the unified copy_from_user intead of multiple duplicated copy_from_user codes in every ioctl cmd
Fix the demo crash when it fail to execute before init_workers.

The root reason is that the wdata is initialized in init_workers and there is no check of wdata in exit_cleanup.
So the program will crash if it fail to execute before init_workers.
Merge branch 'master' of github.com:fastos/fastsocket