xlib: fix memory leak on Display close

The XMesaVisual instances freed in the visuals table on display close
are being freed with a free() call, instead of XMesaDestroyVisual(),
causing a memory leak.

Signed-off-by: John Sheu <sheu@google.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

src/mesa/drivers/x11/fakeglx.c

@@ -794,7 +794,7 @@ destroy_visuals_on_display(Display *dpy)
       if (VisualTable[i]->display == dpy) {
          /* remove this visual */
          int j;
-         free(VisualTable[i]);
+         XMesaDestroyVisual(VisualTable[i]);
          for (j = i; j < NumVisuals - 1; j++)
             VisualTable[j] = VisualTable[j + 1];
          NumVisuals--;

src/mesa/drivers/x11/xm_api.c

@@ -856,6 +856,7 @@ XMesaVisual XMesaCreateVisual( XMesaDisplay *display,
                                 accum_red_size, accum_green_size,
                                 accum_blue_size, accum_alpha_size,
                                 0)) {
+      free(v->visinfo);
       free(v);
       return NULL;
    }