Improve basic error checking in sceAtrac

Almost all functions return errors when passed an invalid atrac id, but we weren't doing that.  I tested each one.  The majority of those also returned errors if there was no buffer attached yet, for a valid atrac ID.

Also, tested and verified errors when passing invalid data to a few more functions.  I couldn't test sceAtracSetMOutDataAndGetID() and sceAtracSetMOutData(), because I got "not yet linked" errors for them.  I guess they're in libraries on umds only.

Games still play music, but last time I changed atrac it broke stuff.  And I don't know of anything this fixes, but there is the possibility of a game relying on these error codes.

-[Unknown]