LastMileLogger: fix logging call

Add a missing flush() to a logging call.

(cherry picked from commit 7d6878d893569c9cdaa66a96e36def125f599688)

Bug: 73094025
Test: m javac-check-wifi-service RUN_ERROR_PRONE=true
Test: tests/wifitests/runtests.sh -e class com.android.server.wifi.LastMileLoggerTest (on walleye)
Merged-In: I231d936117ee5425d9108e04db831cf86d9bdfe2
Change-Id: I231d936117ee5425d9108e04db831cf86d9bdfe2
1 file changed