CMA: Adding support for new kernels
CMA: Adding support for new kernels

In Ubuntu 15.10 and the latest kernel CMA changed its default behaviour.
Now it can break up the transmission in the middle of iovec (with a single entry iovec !).
This patch adds special handling for this scenario.

Signed-off-by: Pavel Shamis (Pasha) <493dea064a9960bb6256b5a6f35a2691a450fa47@gmail.com>

sergsagal1/ucx_rocm,shssf/ucx,abouteiller/ucx,abouteiller/ucx,abouteiller/ucx,sergsagal1/ucx_rocm,sergsagal1/ucx_rocm,abouteiller/ucx,shssf/ucx,shssf/ucx