Remove reduntant re-schedule

Calls to BleScannerInterface are already made using jni thread.
Also all this calls do is scheduling to BTA thread, so remove
unnecessary call to do_in_jni_thread

Bug: 30622771
Test: sl4a FilteringTest
Change-Id: I2c799dde720f9bc694fecacd6d3959b96c1b9ba8