bootindex: support to set a existent device's bootindex to -1

When set a device's bootindex to -1, we remove it from global
fw_boot_order list.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

bootdevice.c

diff --git a/bootdevice.c b/bootdevice.c
index aac0ffb..a38479a 100644
--- a/bootdevice.c
+++ b/bootdevice.c
@@ -77,6 +77,7 @@
     FWBootEntry *node, *i;
 
     if (bootindex < 0) {
+        del_boot_device_path(dev, suffix);
         return;
     }