fix potential memory leak

use delete before return

Change-Id: I5449ad90bb6910f057bd825b722c9803a7343c34
Fix incorrect FloatMath documentation.

Change-Id: I30bbe500e634b73f3456ccc797106ad261fd0ce7
Leak in ToneGenerator_native_setup

Failure in ToneGenerator::isInit causes a leak.
lpToneGen should be deleted.

Change-Id: I48df7a328fed01be8412d5449ee0753dad3c101f