input: remove unused mouse_handlers list

Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

ui/input-legacy.c

@@ -57,8 +57,6 @@ struct QEMUPutLEDEntry {
 
 static QTAILQ_HEAD(, QEMUPutLEDEntry) led_handlers =
     QTAILQ_HEAD_INITIALIZER(led_handlers);
-static QTAILQ_HEAD(, QEMUPutMouseEntry) mouse_handlers =
-    QTAILQ_HEAD_INITIALIZER(mouse_handlers);
 
 int index_from_key(const char *key)
 {