initialize hoverlayer_scrollnote_preview in control_create

sure, I'll find a better name to this variable

Author: RaviScriptDev

scripts/control_create/control_create.gml

@@ -395,6 +395,7 @@ function control_create() {
 
 	mousewheel = 0
 	changepitch = 1
+	hoverlayer_scrollnote_preview = 0
 
 	keynames = ["A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#"];
 	keynames_flat = 0