Minor cleanup / optimization of font-size defaulting.

jquery.flot.js

@@ -735,9 +735,11 @@ Licensed under the MIT license.
             // since the rest of the code assumes that they exist.
 
             var i, axisOptions, axisCount,
+                fontSize = placeholder.css("font-size"),
+                fontSizeDefault = fontSize ? +fontSize.replace("px", "") : 13,
                 fontDefaults = {
                     style: placeholder.css("font-style"),
-                    size: Math.round(0.8 * (placeholder.css("font-size") ? +placeholder.css('font-size').replace("px", "") : 13)),
+                    size: Math.round(0.8 * fontSizeDefault),
                     variant: placeholder.css("font-variant"),
                     weight: placeholder.css("font-weight"),
                     family: placeholder.css("font-family")