analysis: Add additional assertion to troubleshoot test failure

analysis: Add additional assertion to troubleshoot test failure

The axis range in the tested SWTChart doesn't have the correct range.
It would be interesting to know if the window range of the trace is
correct.

Change-Id: I001787016a5b3d78b83b526175d8a1e9656e2790
Signed-off-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/84277
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Tested-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-by: Hudson CI