gfio: use glib hash for tab lookup

Not really a CPU saver, but it reduces the amount of code we have
to maintain by getting rid of the list lookup.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/gfio.h b/gfio.h
index 4a60292..dd4ee3d 100644
--- a/gfio.h
+++ b/gfio.h
@@ -3,7 +3,6 @@
 
 #include <gtk/gtk.h>
 
-#include "flist.h"
 #include "stat.h"
 #include "thread_options.h"
 #include "ghelpers.h"
@@ -68,7 +67,7 @@
 	pthread_t t;
 	int handler_running;
 
-	struct flist_head list;
+	GHashTable *ge_hash;
 } main_ui;
 
 enum {
@@ -91,7 +90,6 @@
  * Notebook entry
  */
 struct gui_entry {
-	struct flist_head list;
 	struct gui *ui;
 
 	GtkWidget *vbox;