usb: rmnet: Queue usb buffers to h/w when skb queue is empty

rx buffers are not given to usb h/w when skb queue was empty which
is resulting in data stall. Fix data stall by queueing usb buffers
when skb queue is empty.

Change-Id: Id71bb4e3628efd9d76ec90431871faee7b2831ee
Signed-off-by: Vamsi Krishna <vskrishn@codeaurora.org>
1 file changed