revert; bugs should be fixed, not ignored

stepmania/src/NoteData.cpp

@@ -372,14 +372,12 @@ bool NoteData::IsHoldNoteAtBeat( int iTrack, int iRow, int *pHeadRow ) const
 		case TapNote::attack:
 			return false;
 
-			//Some songs still have these for some reason.
-		case TapNote::hold_tail:
 		case TapNote::empty:
 		case TapNote::autoKeysound:
 			/* ignore */
 			continue;
 		default:
-			LOG->Warn( "Found unknownnote type: %d.  Ignoring note.", tn.type );
+			FAIL_M( ssprintf("%i", tn.type) );
 		}
 
 		if( bFoundHead )