Fix empty tag for logcat

to avoid weird display like the following:
08-22 17:17:03.634  1745  1745 D         : createUnique: call
08-22 17:17:03.636  1745  1745 D         : HostConnection::get() New Host Connection established 0xf4b163c0, tid 1745

Test: adb logcat -s HostConnection

Change-Id: Ifef2f14e79ac2fafebfdd346cc7d8c6042359ef1
1 file changed