Revert "[usb]: Fix bug that blocked forerver in skel_read"

This reverts commit 35c5bf4f60b2783ada77b5c31133e99a326fd3d4.
[usb]: Add usb-skeleton.c Makefile and test with g_zero
USB: usb-skeleton.c: fix blocked forever in skel_read

In skel_read,the reader blocked in wait_for_completion before submit
bulk in urb.
Using processed_urb is for retaining the completion in the case that
previous interruptible wait in skel_read was interrupted and complete
before next skel_read.  Replacing completion with waitqueue can avoid
working around the counting nature of completions
and fix the bug.
[progs]: Fix compiling errors