usbip: vudc: Refactor init_vudc_hw() to be more obvious

Current implementation of init_vudc_hw() adds ep0 to ep_list
and then after looping through all endpoints removes it from
that list.

As this may be misleading let's refactor this function
and avoid adding and removing ep0 to eplist and place it
immediately in correct place.

In addition let's remove redundant 0 assignments as ep
array is zeroed during allocation.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>