Update FmodAudioPlayer.cpp

If you run pauseBackgroundMusic and then isBackgroundMusicPlaying (), this returns true when it should return false (I think), This can be tested in the demos:
cocos2d-x-2.2.0/samples/Cpp/TestCpp/Classes/CocosDenshionTest


Also if you run playBackgroundMusic (const char * pszFilePath, bool bloop) with bloop made ​​false returns true call to isBackgroundMusicPlaying () after finishing the music.

This short patch corrects pequenno. :)