Search: fill the inside of the more icon with opaque black

If the more icon is transparent inside, you can see the provider icon below,
which with some icons (like boxes) looks like the plus has a double stroke.

https://bugzilla.gnome.org/show_bug.cgi?id=695581

data/theme/more-results.svg

@@ -14,7 +14,7 @@
    height="16"
    id="svg12430"
    version="1.1"
-   inkscape:version="0.48.3.1 r9886"
+   inkscape:version="0.48.4 r9939"
    sodipodi:docname="more-results.svg">
   <defs
      id="defs12432" />
@@ -25,18 +25,18 @@
      borderopacity="1.0"
      inkscape:pageopacity="1"
      inkscape:pageshadow="2"
-     inkscape:zoom="1"
-     inkscape:cx="8.3155237"
-     inkscape:cy="0.89548874"
+     inkscape:zoom="90.509668"
+     inkscape:cx="6.5009792"
+     inkscape:cy="8.3589595"
      inkscape:document-units="px"
      inkscape:current-layer="g14642-3-0"
      showgrid="false"
      borderlayer="true"
      inkscape:showpageshadow="false"
-     inkscape:window-width="2560"
-     inkscape:window-height="1376"
-     inkscape:window-x="1200"
-     inkscape:window-y="187"
+     inkscape:window-width="1440"
+     inkscape:window-height="840"
+     inkscape:window-x="0"
+     inkscape:window-y="27"
      inkscape:window-maximized="1">
     <inkscape:grid
        type="xygrid"
@@ -90,6 +90,11 @@
          transform="translate(-2,0)"
          width="16"
          height="16" />
+      <path
+         style="fill:#000000;fill-opacity:1;fill-rule:evenodd;stroke:#000000;stroke-width:0;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-opacity:1"
+         d="M 7 5 L 7 7 L 5 7 L 5 9 L 7 9 L 7 11 L 9 11 L 9 9 L 11 9 L 11 7 L 9 7 L 9 5 L 7 5 z "
+         transform="translate(141.99984,397.99107)"
+         id="rect3757" />
       <path
          inkscape:connector-curvature="0"
          style="color:#bebebe;fill:#ffffff;fill-opacity:1;stroke:none;stroke-width:2;marker:none;visibility:visible;display:inline;overflow:visible"