Commit 2e1d7386e2 ('tests: Refactor tshark
running') added a helper function for running tshark. However, it did
not use the filter argument correctly, added an extra -Tfields on the
command line, and failed to use global variable. In practice, this ended
up disabling all the tshark sniffer checks. Fix that by using the filter
argument from the caller and marking the _tshark_filter_arg global.
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Refactor the code to run tshark into its own submodule. This allows
even remembering whether -Y or -R needs to be used for filtering.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
