bug in example in http://man7.org/linux/man-pages/man7/pkeys.7.html void -> int

[Aaron <aaron_ng@xxxxxxxx>]

Hello!

In http://man7.org/linux/man-pages/man7/pkeys.7.html

We have

void
...       wrpkru(unsigned int pkru);

...

int pkey_set(int pkey, unsigned long rights, unsigned long flags)

... returnwrpkru(...

Regards, Aaron