ext4: remove unused variable

Change-Id: I84ad060543714d141d4cd40369b9fa0a8a63f78f
Signed-off-by: Zhao Wei Liew <zhaoweiliew@gmail.com>
USB host: add placeholder function for usb_disable_xhci_ports

needed for compilation without CONFIG_PCI

Change-Id: I03f16bd203fe46f18f1ea87d17e31afd6328a58b
Signed-off-by: Zhao Wei Liew <zhaoweiliew@gmail.com>