Device is left in the busid_table after unbind and rebind. Rebind
initiates usb bus scan and the original driver claims the device.
After rescan the device should be deleted from the busid_table as
it no longer belongs to usbip_host.

Fix it to delete the device after device_attach() succeeds.
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>