accel/hvf: Mention hvf_arch_update_guest_debug() must run on vCPU

Since hvf_arch_update_guest_debug() calls hvf_arch_set_traps()
and hvf_arch_update_guest_debug(), which must run on a vCPU, it
also must. Mention it.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Mads Ynddal <mads@ynddal.dk>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
1 file changed