USB: gadget : Fix RNDIS code to pass USB Compliance tests (USBCV) with g_ether

This patch fixes a bug in the RNDIS code.

Due to this bug gether_connect() fails as the port remains un-initialized.

As a result following USB Compliance Tests were failing.
(1)EndpointDescriptorTest_DeviceConfigured
(2)Interface Descriptor Test.
(3)Halt Endpoint Test.
(4)SetConfigurationTest

The fix aligns rndis code with the CDC ECM for xxx_set_alt().

The above listed USB Compliance test passes with this fix.

Tested working fine on SDP with OMAP 3430.

Signed-off-by: Maulik Mankad <x0082077@ti.com>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>