Fix compile warning
Fix compile warning

imx_usb.c:180:4: Warning: 'return' without value, in function returning non-void

Signed-off-by: Bernhard Walle <0126900a8e0b3a4ca252ce135f6083413ee82854@bwalle.de>

bwalle/imx_usb_loader,boundarydevices/imx_usb_loader