test: fix test step title.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: add interface settings modify tests.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
dabbad: split hardware/software interface settings.

In a close futur, it hardware/software interface should be further taken
apart and maybe get reported seperately.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: create TEST_DEV prerequisite.

The test cases might modify some interface settings which can pertubated
or cut connectivity.
Creating dummy devices are suboptimal because some aspects of them
cannot be changed (e.g. txqlen, speed) and the user need elevated
privileges to use them.

Therefore, all tests must be read-only by default.
the prerequisite TEST_DEV can be set to tell which device is safe to
modify.
It can be set this way:
 - TEST_DEV="eth0" make test

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: remove obsolete DUMMY_DEV prerequisite.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: check txqlen settings on test interface.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: change 'tx qlen' to 'txqlen'.

Making matching option and output string makes things easier to script
test cases.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: add ethtool test prerequisite.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: properly chain multiple cmd in a test step.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: compare interface port to ethtool output.

Added tests to check if the output generated by ethtool about the
interface supports ports matches the one reported by dabba.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>