linux_usbfs: Improve isochronous transfer submission and error reporting

linux_usbfs: Improve isochronous transfer submission and error reporting

The Linux kernel has changed the maximum allowed packet length per
isochronous packet numerous times, which can create difficulties in
trying to report appropriate errors back to the user when submitting too
large of a packet on older kernels.

In an attempt to improve this situation, this commit adds logic that
will use different per-packet limits based on the detected kernel
version. Additionally, the logic has been improved to split URBs based
on the number of isochronous packets per URB, which is currently (and
has been forever) limited to 128.

Finally, the error reporting during URB submission has been improved to
catch and report errors relating to the transfer length being too large.

Closes #118

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>