radv: Make NGG query emission a dirty flag - CPU overhead part 3

CPU settings used for testing:

# Set all cores to use performance governor
for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do echo performance > $i; done
# Disable CPU boost
echo 0 > /sys/devices/system/cpu/cpufreq/boost
# Disable address space randomization
echo 0 > /proc/sys/kernel/randomize_va_space

Test score is the average of 3 runs:

for i in {1..3}; do echo "--- run $i"; ./vkoverhead -test 0 -duration 10; done

commit	3900X score	i7-6700K score
main	21486	26418
radv: Make NGG query emission a dirty flag.	22239 (+3.5%)	28821 (+9%)