libbladeRF: Move the submit_stream_buffer up one layer to usb.c

[jenselofsson]

Removed [lusb|cyapi]_submit_stream_buffer and replaced it with submit_stream_buffer in usb.c, as pointed out in issue #439 . Also added the functions [lusb|cyapi]_get_num_avail and [lusb|cyapi]_get_num_transfers, since usb.c need to know the values of num_avail and num_transfers.

[jynik]

@jenselo Thank you so much for tackling this. I just wanted to ACK that I've seen this and will be looking to test and merge soon.

If you're up for it, mind pinging me for confirmation of any of the following.

• Build tests with MSVC 2012, 2013, 2015
• Build tests with gcc
• Build tests with clang
• Bill of clean health from clang's scan-build tool (I am aware of a false positive from previous code)
• Bill of clean health from some transmit tests programs and general usage

I will likely do all of the above regardless, but it's a bit easier to sleep at night when the patch author has confirmed items such as these independently. 😉

[jenselofsson]

Sorry for the delay.
I have built/compiled it with both clang 3.5.0 and gcc 4.9.2, and it builds and runs just fine, both for Debug and Release type.

scan-build returns:
scan-build: Removing directory '/tmp/scan-build-2016-06-07-211422-12375-1' because it contains no reports.
scan-build: No bugs found.

The libbladeRF_tests builds without problem, and I'm running them now. Unfortunately I don't have access to Windows, so I can't test with MSVC.

[jynik]

@jenselo No worries. I'll definitely be merging this, but I may wait until after the next release I post. There's a few CyUSB issues that I want to look at, without introducing any other changes into while debugging.

[rtucker]

G'day,

Sadly this PR fell through the cracks and it will no longer apply cleanly :(

If this is still something you're interested in and are able to rebase it against master, please open a new PR and reference this one and we'll take a look!

Thanks for your patience, and I'm sorry that we dropped the ball on this one.