Bugfix #33019

Grease Pencil draw - started with button from Toolbar - failed. Needed proper
event check.

source/blender/editors/gpencil/gpencil_paint.c

@@ -1648,7 +1648,7 @@ static int gpencil_draw_invoke(bContext *C, wmOperator *op, wmEvent *event)
 	 * painting should start immediately. Otherwise, this was called from a toolbar, in which
 	 * case we should wait for the mouse to be clicked.
 	 */
-	if (event->type) {
+	if (event->val == KM_PRESS) {
 		/* hotkey invoked - start drawing */
 		//printf("\tGP - set first spot\n");
 		p->status = GP_STATUS_PAINTING;