modesetting: call xf86_cursors_fini during CloseScreen

Add matching call for xf86_cursors_init to clean memory, as during
initialization it allocates memory (depends, but is something like ~256Kb)
and it leaks when XServer resets.

Signed-off-by: Tautvis <gtautvis@gmail.com>

hw/xfree86/drivers/modesetting/driver.c

@@ -2183,6 +2183,10 @@ CloseScreen(ScreenPtr pScreen)
         ms->drmmode.shadow_fb2 = NULL;
     }
 
+    if (!ms->drmmode.sw_cursor) {
+        xf86_cursors_fini(pScreen);
+    }
+
     drmmode_uevent_fini(pScrn, &ms->drmmode);
 
     drmmode_free_bos(pScrn, &ms->drmmode);