audioflinger: Fix to release wakelock after closeoutput

-In DirectTrack destructor, closeOutput is called after
releaseWakelock is done. This may sometimes result in
power collapse happening even before actual close
sequence of Audio path is completed and will result
in high power consumption.
-Release wakelock only after closeOutput is done
in directtrack destructor.

(cherry picked from commit fb48938f73e335ac66c83e6adba96431e050ec94)

Change-Id: Ib8d05a38f28d7e2f0bdf9e420e5db526cf874bc6
CRs-Fixed: 430786