Update RWF_* constants
Update RWF_* constants

* xlat/rwf_flags.in: Add RWF_DSYNC and RWF_SYNC introduced
by linux kernel commit v4.7-rc1~158^2~1.

cuviper/strace,Saruta/strace,Saruta/strace,cuviper/strace,cuviper/strace,Saruta/strace,cuviper/strace,Saruta/strace,cuviper/strace,Saruta/strace