Revert "usb: gadget: NCM: Protect dev->port_usb using dev->lock"

This reverts commit c9ffc787 as it was
reported to be broken.

Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Jim Baxter <jim_baxter@mentor.com>
Cc: Harish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>