Lessen EACCES log spam

Test: as follows
    - built, flashed, booted
    - started tethering, observed dnsmasq log messages but no
      EACCES spam
Bug: 32163131
Bug: 38364896
Bug: 80229031
Change-Id: I719c81c326c95186576c7186cc25f4eda24091fa
1 file changed