Fix clock_nanosleep when interrupted by a signal

This patch fixes the time64 support (added by 2e44b10b) where it
misses the remaining argument updated if __NR_clock_nanosleep
returns EINTR.

Checked on i686-linux-gnu on 4.15 kernel (no time64 support) and
on 5.3 kernel (with time64 support).

Reviewed-by: Alistair Francis <alistair23@gmail.com>