Check the service pointer on aidl deinit to avoid
a possible segfault.

Bug: 218900981
Test: adb root
      adb shell
      /vendor/bin/hw/hostapd -i wlan0 -B /data/sigma_dut-ap.conf
      # Should terminate with no output.
Change-Id: I5b814e2bd7539f41136b9de00161eee2301e8d51
1 file changed