Fix task state unknown with Linux >= 4.1

Fix task state unknown with Linux >= 4.1

The control flow view displays the task state as WAIT_UNKNOWN with
newer kernels. This is caused by a new task state value. The mask is
adjusted to fit this new value.

The fix is backward compatible.

Change-Id: I568dd51cd597ab64819cc6a83a3c6f06ec859489
Signed-off-by: Francis Giraldeau <francis.giraldeau@gmail.com>
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/67377
Reviewed-by: Hudson CI
Reviewed-by: Alexandre Montplaisir <alexmonthy@efficios.com>
Tested-by: Alexandre Montplaisir <alexmonthy@efficios.com>