example_linux_scopevis fails with "data length differ"

[moritzschaefer]

Running the example there are always only around 400-800 sample points.

!@! ~/tmp/Hantek6022API (master) $ python2 examples/example_linux_scopevis.py
data lengths differ!
[('timing', 8192), ('voltage', 609)]
!@! ~/tmp/Hantek6022API (master) $ python2 examples/example_linux_scopevis.py
data lengths differ!
[('timing', 8192), ('voltage', 448)]