Revert "voice fx: fix effect state control logic."

Since this commit was merged, the Echo effect while talking
got much worse. The echo suppression effect doesn't seems to
work at all now.

This reverts commit 602c06af383002698fdc57f72736cf28164d2067.

Change-Id: Ie7335c845797ebbd89adf9dcf13cef9f398152e5