Apply suggestion from @bobrippling

Co-authored-by: Rob Pilling <robpilling@gmail.com>

apps/smartbatt/clkinfo.js

@@ -26,7 +26,7 @@
     var s=24,g=Graphics.createArrayBuffer(24,24,1,{msb:true});
     g.fillRect(0,6,s-3,18).clearRect(2,8,s-5,16).fillRect(s-2,10,s,15).fillRect(3,9,3+batt*(s-9)/100,15);
     g.transparent=0;
-    img=g.asImage("string");
+    return g.asImage("string");
   }
 
   //calls both updates for values and icons.